On 27 February this year, Boris Nemtsov took his girlfriend out to dinner near Red Square. Nemtsov was 55, greying but boyish. He had served briefly as Russia’s deputy prime minister in the late 1990s, but thereafter had been in perpetual opposition. As Vladimir Putin’s grip on power strengthened, Nemtsov’s weakened. But he kept fighting, running for elections and exposing corruption and mismanagement. In February, he was investigating evidence that, despite Kremlin denials, Russian soldiers were fighting in Ukraine.

After dinner, Nemtsov and his girlfriend, a 23-year-old model – Nemtsov might have got older, but the ladies stayed the same age – walked home, across a bridge over the Moscow River. There weren’t many pedestrians around; a winter evening in Moscow is not an ideal time for a stroll. But the setting was spectacular: the Disney domes of St Basil’s Cathedral loomed over Nemtsov’s left shoulder, the Kremlin’s russet battlements over his right. It was a fitting stage for a brave man’s death.

An assailant jumped from a car, shot Nemtsov four times in the back and fled, leaving his body on the tarmac. Within a week, police officers identified a group of men who had been tailing Nemtsov, and on 6 March they arrested Zaur Dadayev, formerly a senior officer in the Chechen security services, and four other men with links to Chechnya. At least until late 2014, Dadayev had reported directly to Alibek Delimkhanov, whose cousin, Ramzan Kadyrov, is the leader of Chechnya.

On 8 March, Zaur Dadayev confessed to the murder. It seemed unlikely that the murder of a figure as prominent as Nemtsov could have taken place without the knowledge of more senior figures. Inevitably, suspicion turned to Kadyrov, who angrily denied any connection to the killing. Writing on Instagram on the day of the confession, Kadyrov speculated about the killer’s motive. He suggested that, as a devout Muslim, Dadayev had been offended by the Muhammad cartoons published by Charlie Hebdo magazine, and sought vengeance on Nemtsov, who had publicly supported the cartoonists. (Dadayev, however, later retracted his confession.)

On 13 March, Kadyrov took to Instagram to make clear that he was being unfairly victimised. “The United States and the west try first to hit those who are most devoted (to Putin),” he wrote. Nevertheless, the allegations have refused to go away. Kadyrov is essentially employed by Putin to stop Chechens from killing Russians, but he has also been linked to a long list of killings. The motives have tended to be, like Kadyrov himself, crude and straightforward: someone threatened his hold on power, and ended up dead. It is not easy to see why he would want rid of Nemtsov but, all the same, Kadyrov’s track record was sufficient for many people to view a motive as unnecessary. (Kadyrov’s spokesman, who I have known for a decade, did not respond to multiple requests via phone, text and email, for comment on this article.)

“The crime clearly leads directly to Kadyrov. I cannot imagine that these men could commit such a terrible crime without, at the very least, informing him,” said Ilya Yashin, a liberal politician and Nemtsov’s political comrade. He, like many Russians, thinks of Kadyrov as a guard dog that has slipped his chain. Putin used the Kadyrov family to crush Chechen separatism, but now Ramzan has broken free.

“Kadyrov stands above Russian law,” Yashin said. “Any attempt to remove him from his job, or to prosecute him, could provoke a new Chechen war. Putin is undoubtedly scared of such a development, which is why he can’t solve the Kadyrov problem.”

Ramzanism is almost the ur-expression of Putinism: equal parts bling, violence, nationalism, kleptocracy and religion

That is one explanation of why the leader of a region within Russia is able to act with such freedom. But it is not the only one, and not necessarily even the most likely. If it were true, Putin might be keeping Ramzan at arm’s length, but he is not. On the contrary: the president has said Kadyrov is like a son to him, while Ramzan says Putin is his idol. They meet regularly, converse warmly, praise each other. Politically, there is little to separate them. Indeed, Ramzanism is almost the ur-expression of Putinism: a philosophy that is equal parts bling, violence, nationalism, kleptocracy and religion.

So, if you’re worried that Ramzan is murdering with impunity and Putin can’t control him, consider the alternative: what if Ramzan is murdering with impunity, and Putin does control him?

The Chechen nation is Muslim, and lives in the mountains on Russia’s southern border. Conquered at the end of the 1850s, the Chechens chafed under both tsarist and Soviet rule and, after the collapse of the USSR, took the opportunity to declare independence. In 1994, Russian generals sent troops to crush Chechnya, but totally miscalculated their opponents’ resolve: the Chechen irregulars humiliated them. There were only around 750,000 ethnic Chechens when the war began, fewer than the one million Russian men who reached military age that year, yet they defeated this supposed superpower. Chechnya was a symbol of just how weak Russia had become. For the Chechens, it was a famous victory, but it was also a hollow one, since peace did not follow. By the late 1990s, Chechnya was outside anyone’s control – a haven for criminals, kidnappers, warlords and Islamists.

Ramzan Kadyrov and his father, Akhmad, then Chechen president, in January 2004. Akhmad was assassinated later that year. Photograph: AFP/Getty Images

When Putin became prime minister in 1999, Chechnya topped his to-do list. He was a novice, but he knew that to re-impose Moscow’s will on Chechnya, he needed a local to give conquest a Chechen face. He found that person in Akhmad Kadyrov, Chechnya’s chief mufti – a man so troubled by the hardline, Saudi-style Islam spreading in his homeland that he was prepared to do a deal with the Russians to stop it. Akhmad had a rough, walrus-like manner, a bulbous nose and an earthy charisma. He organised a Chechen militia – known as the Kadyrovtsy – who helped Russian troops crush his erstwhile comrades.

Putin pacified Chechnya with extreme prejudice. Artillery shattered Grozny; FSB agents abducted thousands of young Chechen men, hundreds of whom were never seen again. The Russian electorate, deeply scarred by their country’s steep decline, loved it. In 2000, though barely known just a year earlier, Putin won the presidency. It was a victory he owed to Chechnya. And he owed Chechnya to Akhmad Kadyrov.

I first met Ramzan Kadyrov on 5 October 2003, his 27th birthday. He was standing outside a polling station in the village of Tsenteroi, in the thickly furred foothills of the Caucasus mountains. We were waiting for his father to vote in an election that would elevate Akhmad to the presidency of Chechnya. Ramzan was sandy-haired, with a low forehead. He had inherited Akhmad’s nose, but none of his presence. Standing in the yard, he looked a little like a teenager too nervous to go into a party, and waddled when he walked. We discussed the leaders of the lingering anti-Moscow insurgency. Ramzan, who ran the Kadyrovtsy on his father’s behalf, praised the insurgents’ military abilities. They should surrender and come to work for his dad, he said.

Kadyrov is vulgar, venal, vicious, venerated and very rich: somewhere between Uday Hussein and the Notorious B.I.G.

They did not take up the offer. Instead, on 9 May 2004, they assassinated Akhmad in a bomb blast in Grozny. Putin received Ramzan that same day, in a meeting aired on all Russia’s main news bulletins. The 27-year-old looked stunned, his blue tracksuit out of place amid the dark panels and glittering ornaments of the president’s office. Though sombre, that moment marked the start of a remarkable political career. With Akhmad gone, Putin had a vacancy for a Chechen satrap, and Ramzan was perfect for the role. Ramzan was not immediately given the top job but, thanks to his control of the Kadyrovtsy, he dominated the republic. In 2007, he assumed the presidency.

In 2010, however, he declared that he would no longer be called president of Chechnya, since Russia should only have one president. Kadyrov is now known, in Russian, as the “head of the republic”. In Chechen, he is called pachchakh, a corruption of the Farsi word padishah, meaning “king”. And he lives like one.

He has built himself palaces, one in Grozny and one in his home village of Tsenteroi, sparred with Mike Tyson, played football with Diego Maradona, and partied with Gerard Depardieu. He has posed with a tiger cub and acquired a stable of horses that race all over the world. He has organised beauty contests and wrestling bouts. He documents his life on Instagram, regularly treating his 1.2 million followers to images of himself praying, working out, meeting officials, hanging with his buddies – all of whom are men with significant biceps. His photos are accompanied by lengthy texts explaining his views on contemporary issues. He is vulgar, venal, vicious, venerated and very rich: somewhere between Uday Hussein and the Notorious B.I.G. None of this appears to bother Putin.

Ramzan Kadyrov with (from left) Gérard Depardieu, Diego Maradona and Mike Tyson. Composite: Rex; Reuters

Last year, Kadyrov announced a new policy of destroying the houses of anyone whose relatives fight against the government, and then exiling them from Chechnya. “Kadyrov’s statement may have been a bit emotional,” said Putin in December, when challenged about his protege’s words. “I think emotions are understandable in such cases.”

Russia Day is on 12 June. This is a slightly ambiguous public holiday, since it marks Russia’s independence from the Soviet Union, something much of the country would prefer had not happened. Kadyrov, however, does not do understatement, and any public holiday is an occasion to showcase his ability to mobilise large groups of people. This year, from early in the morning, buses brought students, teachers and other state employees to central Grozny to hear speeches.

It was fiercely hot. The sun had soaked into the acres of tarmac and heat radiated into the soles of my shoes. Students sought out shade while they checked their phones. They carried professionally printed portraits of Putin, Akhmad and Ramzan Kadyrov, as well as banners declaring which institutions they studied at. I had hoped Kadyrov would address the crowd, but instead he sent a couple of underlings, who recounted modern Chechnya’s founding myth: how Akhmad rescued the Chechens from westerners, terrorists, Islamists and other malefactors; how Ramzan took on his mantle, and transformed the republic into something magnificent.

When Putin won the presidency in 2000, Grozny was a wasteland. To prevent a damaging battle, the Russian army had bombarded it until the guerrillas withdrew. Apartment blocks were smashed, steel beams scrunched and metal fences shredded by shrapnel. At least 8,398 Russian servicemen died in the two Chechen wars, according to conservative statistics provided by the Russian general staff and defence ministry. Estimates of the total number of Chechen deaths in the two wars have ranged from 150,000 to as high as 300,000. Even in 2003, when Chechen resistance was reduced to nocturnal raids, roadside bombs and suicide attacks, every intersection held a military post, an ugly tangle of breeze blocks and barbed wire. Foreign journalists could only visit Chechnya with a military escort, and spent the night in the Russian base at the airport.

Grozny is now unrecognisable. Kadyrov has spent billions making a city that proclaims his glory, and it shows. The airport accepts civilian flights; the markets are bustling; the apartment blocks have been repaired. At the centre of Kadyrov’s capital is a high-rise cluster called Grozny City, including a hotel reputed to be the only place in Chechnya that serves alcohol. The flank of the tallest tower bears the scrolling message “WE LOVE PROPHET MOHAMMED”, and above the message is a portrait of Akhmad Kadyrov. From there, Akhmad Kadyrov Avenue runs to the Akhmad Kadyrov mosque, and on to the huge gold obelisk of the Akhmad Kadyrov museum.

The museum minutely documents its subject’s life: his time at a seminary in Uzbekistan, his visits to the Middle East, his period as head of Chechnya, the day he died. Vitrines contain his tie, his shoes, a shirt, two jackets, a coat and a hat. There is also a Betamax videotape recording of him receiving an honorary professorship at the Modern Academy of the Humanities, an obscure Moscow university that offers distance learning.

On the day I visited, a woman in a pink headscarf was lovingly showing a replica of Akhmad’s office to a group of teachers. “Until the end, he was a devoted son of his people, a real man,” she said, while two of her audience filmed her on their iPads. “He gave his life, and peace came.” The museum contained no photos of Grozny in ruins, or of the separatist leaders, or of Russian troops in Chechnya. Its message was relentless: only the Kadyrovs matter.

Much of the money for Grozny’s transformation into a city-shaped tribute to the Kadyrov family has come from the Russian federal budget, which has sent the equivalent of billions of pounds to Chechnya over the last decade and a half. Even now, with the Russian budget squeezed by recession and sanctions, Chechnya receives around 57bn roubles a year from Moscow (about £550m).

Other cash flows from the Akhmad Kadyrov Fund, a non-transparent foundation headed by Kadyrov’s mother, Ayman, set up “to provide charitable assistance to citizens in need and to create jobs for the republic’s population”. The money comes from allegedly voluntary donations from businessmen and ordinary Chechens. Russia’s upmarket Kommersant daily has reported that the foundation has, among other things, paid for Chechens to go on the haj, equipped a hospital and bought motorbikes for the Night Wolves, a gang of Putinite bikers. The fund also paid for a lavish party which took place in 2011 on Kadyrov’s 35th birthday, which Seal, Jean-Claude Van Damme and violinist Vanessa-Mae attended, along with Hilary Swank. (Swank later apologised for having attended.)

Ramzan Kadyrov is joined by Jean-Claude Van Damme and Hilary Swank at his birthday party in Grozny in 2011. Swank later apologised for attending. Photograph: The Asahi Shimbun

In 2013 Kadyrov announced that Grozny would gain another skyscraper. Billboards bear pictures of a structure that will dwarf anything built to date. Shaped like one of the defensive towers that stud villages in Chechnya’s mountains, but faced with glass and almost 100 metres taller than London’s Shard, it will stand above a crescent-shaped swimming pool orientated towards Mecca. Its name: the Akhmad Tower.

It is hard to assess Kadyrov’s true popularity, since ordinary Chechens are understandably reluctant to speak their mind to strangers. Islamist websites call him an apostate, accuse him of selling his nation for Russian cash, and make clumsy puns on his surname with the Arabic word kafir (unbeliever). My oldest Chechen friends talk of his extravagance and violence with distaste. Many of them yearn for the dream of independence, but they also accept that life is far better now than it was before he took over. At least you can walk the streets after dark.

Much of the toughest criticism comes from the group that might be expected to approve of him most strongly: Russian nationalists. Anti-corruption campaigner and opposition politician Alexei Navalny’s slogan “Stop Feeding the Caucasus” plays on resentment in Russia over how much money has gone to rebuild Chechnya, suspicion that Kadyrov has stolen it for himself, and concern that ethnic Russian regions receive less.

“Kadyrov has managed to get himself in a position where he is the supreme decision-maker in Chechnya, and the spending of tremendous transfers [of money] goes pretty much unchecked by the federal authorities,” said Vladimir Ashurkov, a Navalny ally who was recently granted asylum in London. “The distinction between his personal money and government funds is blurred.”

The distinction between his personal powers and the government is blurred, too. Earlier this year, a teacher in Grozny gave a pile of poems to a contact who has access to government officials. The teacher wanted a new flat, and wanted the poems passed on to Ramzan. Among the poems’ titles were: “Ramzan, Thanks”; “Thanks, Ramzan”; “To Ramzan Kadyrov”; “To A Chechen Woman” (about Ramzan’s mother); “The First President” (about Ramzan’s father); and “Thanks, Ramzan” (again).

Such appeals have a long history in Russia, where peasants often asked the tsar for justice or gifts. Ordinary Russians do the same to Putin during a yearly phone-in (in this year’s show, he gave a schoolgirl a puppy, and offered to intercede for a young man whose girlfriend wouldn’t marry him). But this is new to Chechnya, which has always had a horizontal society, with prestige accorded to elders or religious leaders, not to politicians.

Before the Russian conquest of Chechnya, which was finally completed in 1859, Chechens lived in villages, without a central government to collect taxes and dispense favours. Thereafter, Chechens were not trusted to run their own territory. Well into the 1980s, non-Chechens outnumbered locals in all positions. The post-Soviet chaos meant there was no opportunity for serious patronage. Kadyrov is Chechens’ first experience of a local boy really being in charge, and he micro-manages.

In May, local television showed him scolding a group of men and women, who stood with their heads bowed in the hall of his palace, beside a model of the Akhmad Tower, for having spread a rumour that an ambulance had been called for a 17-year-old after her wedding to a police chief. “Take your women off social media,” he told the men. “If I hear of this again, it will not go unpunished,” he told the women. He stages such interventions regularly, but they have not stopped Chechens gossiping, and Kadyrov is their favourite topic. They talk of his multiple wives, of his palaces, of his wealth, and of his alleged killings.

One of the two underlings who addressed the crowd on Russia Day, was Jambulat Umarov, Kadyrov’s minister for external relations. I was unable to hear much of his speech over the sound of a secondary school teacher next to me talking to her sister on her gold iPhone 6. But from what I could gather, he seemed like a good person to ask about Kadyrov, in the absence of the man himself.

We met in Umarov’s office, where there was a wolf pelt over the back of the sofa. Umarov has decades of experience as an academic, and speaks Arabic and English fluently, but he was nervous, repeatedly checking with my translator (I don’t speak Chechen, which is unrelated to Russian) that he was staying on-message. It was a message that began with a 25-minute history lesson, delving back into the earliest days of Chechens’ relations with Russia, and addressing their repeated attempts to break free.

“This continued until we heard the sermons of the great preacher who became the father of the nation. That was Akhmad Kadyrov,” he explained, while he fiddled with a sheet of paper on his desk. “Now, thanks to Putin’s support, we have imposed order. No one interferes in our affairs.”

Any woman would dream of being his wife, even the fourth. He’s healthy, strong, not poor. He could support a family well Jambulat Umarov

Is Kadyrov vastly wealthy?

“Look, if Ramzan has been given a horse, he doesn’t just sell it and pocket the $500,000. This horse instead expresses the glory of Russia, the glory of Chechnya. We are proud of the horses … Any present supposedly given to Ramzan Kadyrov, it is a present to the whole nation,” he explained.

And how many wives does Kadyrov have?

“I think any woman would dream of being his wife, even the fourth. He’s nice, good-looking, healthy, strong. He’s not poor. He could support a family well.”

Chechen resistance has shrivelled since its 1990s heyday, when the rebels could field thousands of men. The Putin-Kadyrov counter-insurgency strategy has been so ruthless that the opposition resembles a death cult: only people not just willing to die, but actively wanting to, will have anything to do with it. On 4 December last year, Kadyrov was in Moscow for Putin’s state of the nation speech. In the small hours of the morning, jihadist guerrillas killed three traffic policemen in Grozny and then took over the Press House, a glass-faced block that houses Chechnya’s state media.

Such attacks are rare, so it was embarrassing for Kadyrov that his security services had failed to prevent one on the eve of an important political event. Kadyrov scrambled home to take charge. According to Russia’s anti-terrorism committee, all 10 of the guerrillas died, but they killed 11 more officers, wounded dozens more, and wrecked the Press House. “Dogs will die like dogs,” Kadyrov wrote on Instagram, beside a photo of a man’s legs and lower torso, lying in a pool of blood.

It was at this time that Kadyrov pledged to destroy the houses of rebels’ relatives. When human rights activists complained, their offices were set on fire, and Kadyrov accused them of aiding terrorism. According to Memorial, a Russian rights group, security services detained dozens of young men suspected of assisting the guerrillas, identifying them by their style of facial hair. Kadyrov has declared that anyone who shaves his moustache, but not his beard, is an extremist.

Kadyrov pictured in 2006 with his pet tiger. Photograph: Vladimir Velengurin/Pravda

According to activists from Russian and international human rights organisations (who prefer not to be identified by name, out of fear of reprisals), detentions go in waves, following a militant attack such as this one. First the attackers’ friends and relatives are picked up, and tortured. They incriminate other friends and relatives, who are picked up too. If detainees refuse to confess, they are killed. If they confess, the confessions are used in court, and the young men are jailed.

At least 250,000 Chechens have sought asylum in the west since 2000, and around 200,000 Chechens live in Russia, outside Chechnya. In total, therefore, almost half Chechnya’s prewar population of one million (of whom about a quarter were not ethnic Chechens) has left the republic. According to the 2010 census, the current population of Chechnya is 1.25 million, but that figure is probably inflated: more people in the census means more money for Kadyrov.

Among the exiles were the Tsarnaev brothers, who bombed the Boston marathon in 2013, as well as several hundred Chechens fighting with Islamic State. Others fight for Ukraine against pro-Russian separatists. The vast majority of Chechens abroad live peacefully, however, and in 2008, I spent several weeks travelling among them while researching a book. In Vienna, I found Umar Israilov. He had been a member of the armed resistance, but was detained in late 2003, shortly after Akhmad Kadyrov was elected president. His captors wanted him to confess to murdering security personnel. At one point, he told me, Ramzan Kadyrov himself came in and beat him. After Israilov revealed the location of a weapons cache, they put him through an amnesty system which allowed rebels to surrender without legal consequences (many of them joined Kadyrov’s own armed forces, as did Umar for a while). When the opportunity arose, he fled to Europe. Ramzan Kadyrov did not take that well, and sent officers to pick up Israilov’s father, Sharpudi.

“They had this big sports hall. That’s where they tortured people,” Sharpudi told me this year from his new home outside Russia. (His wife asked me not to reveal the location.) They tied one of Sharpudi’s legs to a billiard table, and eight men took turns beating him. Then they drenched him with water and produced a hand-cranked generator. “The faster the handle turned, the more voltage there was. You scream like a … I don’t know. It’s impossible to withstand this. It feels like every joint in your body is being torn apart.”

After four days, Sharpudi revealed his son’s whereabouts but was held captive in a basement for a further 11 months. When Sharpudi was released, he and Umar appealed to the European court of human rights. Umar wanted to make a home in Austria for his family, and he wanted to expose what Kadyrov had done. In January 2009, Israilov was shot dead on the street in Vienna. Three Chechens were jailed for the murder, and Austrian prosecutors accused Kadyrov of having ordered it. Kadyrov admitted in 2009 to having sent people to talk to Israilov, but denied having had him killed. “Umar personally saw how Kadyrov tortured people. For Kadyrov he was a very dangerous witness,” Sharpudi told me.

In Grozny, I drank coffee with a human rights activist who despaired of the vulnerability of Chechens picked up by Kadyrov’s officers. “We’re between the Islamists who want us to live by the sharia, and Kadyrov, who dreams of us living by his rules,” she said, and tailed off.

On 13 June 2015, a Saturday, Grozny’s newest sporting venue, the 5,000-capacity Coliseum, hosted an evening of mixed martial arts. The organisers had invited fighters from around the world to match lads from the local club, which was named after Akhmad Kadyrov. It was almost, but not quite, a full house. On a platform level with the octagonal cage in which the fighters would assault each other, was a row of gilded sofas, scattered with red cushions, which still lacked occupants. It was no secret who those places were reserved for, and why we were waiting.

At 6.47pm, there was a roar from the far side of the arena. The spectators stood; men lifted children. It was Kadyrov, looking squat in a burgundy tracksuit, bearded, followed by his usual gaggle of men. He settled into his sofa and looked up expectantly. Pounding Chechen turbo-folk ushered the first contestant into the ring. He was a Ukrainian, and lasted 1min 38sec. His conqueror jumped on to the cage wall and gestured in triumph. Kadyrov gave him a thumbs-up. The evening had begun well.

In bout two, a Kazakhstani fighter tapped out 15 seconds into the second round. In bout three, a Crimean didn’t last that long; a leg lock to the head finished him in 2min 49sec. By bout four, the turbo-folk, the strobe lights and the procession of outclassed foreigners was beginning to blur a little. In bout six, a Croatian got punched in the face and fell over. His Chechen opponent sportingly let him up again, then kicked him in the head. Kadyrov grinned widely. His neighbour mimed the fighter’s collapse, falling backwards on to the sofa cushions, like a felled tree.

Kadyrov was constantly on his feet, urging his fighters on. They rewarded him after each bout with a cuddle

Bout 14 featured a 40-year-old Brazilian, who looked terrified, the rolls of fat above his tight trunks shaking. After 42 seconds, the local boy – nicknamed the Lion of Dagestan – drove a punch through his guard. The Brazilian crumpled like a shot deer. I appeared to be the only person troubled by this increasingly dangerous farce. Kadyrov hooted with laughter and the crowd roared.

Kadyrov was constantly on his feet, gesturing his fighters to greater efforts. They rewarded him after each bout with a leap on to his platform and a cuddle. They did not embrace chest to chest as equals, however, but with an awkward bow, their right ears pressed to his right nipple. At last, almost four hours after the show began, the perma-tanned announcer ushered in bout 16, the big one, the finale. A Brazilian heavyweight, aged 32, was up against “the Chechen Lion”, Abdul-Kerim Edilov. Edilov came slowly, perhaps because he had Kadyrov’s seven-year-old son, Adam, on his shoulders – reason enough for anyone to take their time going downstairs. Adam waved a Chechen flag emblazoned with Akhmad’s face. Ramzan beamed; three generations of Kadyrovs acclaimed as one.

The bell rang; the fighters touched gloves. The Brazilian took a kick to the thigh, reeled back and fell. It was over in 26 seconds. Kadyrov pumped his fist and jumped into the ring. Adam was there too, dancing to the cheering crowd. Trainers and friends pushed in, posed for a photo, grinning. A cannon fired golden confetti on to their heads. The Brazilian was still down on the canvas, unable to stand. No one paid him any mind.

A full list of people Kadyrov is accused of having had killed would be long, but here is a selection: investigative journalist Anna Politkovskaya (shot in Moscow in October 2006); FSB commander Movladi Baisarov (shot in Moscow in November 2006); rights activist Natalia Estemirova (abducted from Chechnya and shot in July 2009); pro-Moscow Chechen Ruslan Yamadayev (shot in Moscow in September 2008); Ruslan’s brother Sulim Yamadayev (shot in Dubai in March 2009; Interpol has issued a wanted notice for Kadyrov’s cousin, Adam Delimkhanov, in connection to the crime). Isa, a third Yamadayev brother, whose clan changed sides at the same time as the Kadyrovs and who were rivals for power in Chechnya, survived an assassination bid in July 2009. He wrote an open letter to the Kremlin, complaining that he was being hunted.

“This hunt is being conducted not by savages in the Amazon jungle, but in the capital of our country, by superficially respectable officials with $200,000 Bovet watches,” said the letter, which was published in the Russian tabloid Moskovsky Komsomolets. (Kadyrov was well known for his Bovet watch at that time). “Can all of Kadyrov’s opponents be dubbed enemies of Russia and be killed?”

Kadyrov in Russian military uniform in Grozny in May this year. Photograph: Musa Sadulayev/AP

The Kremlin has awarded both Akhmad (posthumously) and Ramzan its highest decoration. They are heroes of Russia, and their official portraits invariably show them wearing their five-pointed stars. For heroes of Russia, the Kadyrovs have a distinctly anti-Russian past, however. If you look online, you can easily find footage of Akhmad alongside the most extreme anti-Moscow jihadis of the 1990s. When challenged by a journalist over whether he really said every Chechen should kill 150 Russians, Akhmad clarified his position: “I said kill as many as you can.”

It is unsurprising, therefore, that many Russians wonder just where Ramzan Kadyrov’s loyalties lie. Through the amnesty programme, Kadyrov has amassed an army at least as potent as anything the separatists fielded in the 1990s. The question is whether he has created an independent state via the back door. He denies it, of course, but it was a question I took to Magomed Khambiyev, once the defence minister of the breakaway Chechen government, now a member of Kadyrov’s tame parliament.

We met in the Al Pachino, Grozny’s closest equivalent to a hipster cafe. At 52, Khambiyev has grizzled hair, crows’ feet around the eyes and two gold teeth. He was simply dressed in a white linen shirt and still wore a heavy silver ring bearing the wolf-and-moon symbol of independent Chechnya.

Khambiyev surrendered in March 2004, after years hiding in the forest, trying to keep the resistance together. His surrender was not exactly voluntary. A relative came to him with the message that Kadyrov would exterminate his family if he did not give himself up. But, he said, he did not regret it. “If I had stayed there, in the forest, I would only have made things worse for my people and for myself, for my relatives, my neighbours,” he said. “My relatives would have long ago ceased to exist.”

In Chechnya’s parliament, he represents United Russia, Putin’s party. So, what does he think about Putin, the man who crushed his dreams of independence? “Our president is a Chechen, our interior minister is a Chechen, all the ministers are Chechens, and I speak to them in Chechen,” he said. “I don’t think about Putin. I think about Kadyrov. I don’t need to think about Putin. Honestly, I’m not interested in what’s happening in Russia.”

Putin cultivates an enigmatic, standoffish persona, but Kadyrov has no time for such subtlety. He has 300,000 followers on Mobli, 235,000 on Twitter, 241,000 on Vkontakte (a Russian site similar to Facebook), as well as a devoted audience on LiveJournal and Instagram – and he keeps them updated on his opinions several times a day. He spends a lot of time talking up the merits of sport and Islam, but the subjects he reserves most passion for are Putin and the west. Putin is responsible for all that is good in politics; the west is responsible for all that is bad.

Kadyrov has been criticising the west for seeking to surround and undermine Russia for years, but only recently has Putin caught up with him. He has long been a bellwether to national trends in other ways, too. In 2012, Putin won re-election amid huge protests against electoral fraud. In Moscow, thousands of activists observed proceedings and Putin won just 48% of the vote. In Chechnya, where few activists would dare observe anything, Putin won all but 616 of the votes cast.

Putin and Kadyrov together in 2007. Photograph: Dmitry Astakhov/AFP/Getty Images

This may be key to Putin’s continued enthusiasm for Kadyrov. There are times when you need every vote you can get, and it’s nice to know where you can find 611,578 without having to worry. And there are times when it is useful to have a few hundred plausibly deniable troops, such as the Chechens who went into Ukraine last year to stiffen the Donbass separatists’ resistance to Kiev’s army.

Kadyrov has had a lot to say about the “fascists” supposedly in power in Kiev (the European Union has imposed sanctions on him as a result) and, after Nemtsov’s murder, wrapped them into his conspiracy theory: “The sentence issued against Nemtsov in some western capital could have been carried out by the Ukrainian special services.”

Putin’s system can be flexible, and sometimes smart. There are times one needs someone like Kadyrov to do dirty things Andrei Soldatov

Meanwhile, the man identified in June by Russian investigators as the murder’s mastermind, Ruslan Geremeyev, a Chechen police officer, was living openly in Chechnya after the killing, then left for the Gulf when Moscow officers began to look for him, Russian media reported in August. Investigators have said that Dadayev named Geremeyev as the man who ordered him to fire the fatal shots. Without Geremeyev, who is himself unlikely to have initiated the murder without orders, the investigation falls apart. Without Putin’s intervention, there is nothing investigators can do to force Kadyrov to cooperate. And it doesn’t look likely that Putin will intervene. On 9 March, the Kremlin awarded Kadyrov the Order of Honour, less than 24 hours after he had praised Dadayev as a “true patriot” on Instagram.

Andrei Soldatov, a journalist who has researched Russia’s security services since the earliest days of Putin’s reign, said this was typical of Putin, who has many uses for a blunt instrument. “Putin’s system can be flexible, and sometimes smart. There are times one needs someone like Kadyrov to do dirty things,” he said. “It’s a very good game, and all the players are happy to play their roles. The people behind Nemtsov’s assassination know how useful it is to use Chechens as executioners, given the predictable reaction from Kadyrov, it means the investigators never get further.”

That explains why, although Kadyrov has been fingered for the Nemtsov killing, many people blame someone higher: his boss in the Kremlin, the man who created the environment in which Kadyrov thrives.

“The government, with the help of the media, has spread hatred and aggression in society,” said Zhanna Nemtsova, Nemtsov’s daughter, in a newspaper column in June, just days after she left Russia for Germany, out of fear for her life. “The result is the deaths of thousands of people in the Donbass, attacks on opposition and human rights activists in Moscow, Grozny and elsewhere. My dad was a victim of this propaganda of hate.”

She has since sought to sue Russian investigators for failing to question Kadyrov. But even if they did, what good would it do? Once someone like Kadyrov has been let loose, could even Putin bring him back under control? It is classic Putinist ambiguity: perhaps even the president doesn’t know if he can rein in Kadyrov.

On 14 June 2015 it was a sunny morning high in the foothills of the Caucasus range. We were in Benoi-Vedeno, the Kadyrovs’ ancestral village. Men with guns took up positions; and soon there arrived a column of Nissan 4x4s, painted in forest camouflage. The Akhmad Kadyrov Fund had gifted bikes to 500 local boys, and boys and bikes alike waited in the courtyard of the mosque. The car doors opened, and Ramzan Kadyrov vanished into the crowd, pursued by his usual entourage.

Kadyrov wants to transform Benoi-Vedeno into a tourist magnet, and officials had organised a sports day: horse races, motorcycle stunt riders, barbecues, traditional games (next day’s headline: “Ramzan Kadyrov threw a sheep’s leg 10 metres”). That evening, there would be a concert by folk singer Rashana Aliyeva.

I had hitched to the village with some garrulous young men who were organising the concert. They had a relaxed attitude to security, and gave me an all-access pass as soon as I asked for one. That meant I could sit and observe Aliyeva rehearsing, and see when Kadyrov arrived to watch. She tried to look unbothered, but she straightened her back a little, lifted her breasts and moistened her lips. By now, it had started to rain heavily, but Kadyrov brushed away an umbrella. He watched avidly for six or seven minutes before striding off, his men scurrying after him. Aliyeva looked distraught as the rain splashed on to the uncovered front of the stage.

Alvi Kerimov, Kadyrov’s spokesman and the old acquaintance who had ignored my every attempt to communicate with him, noticed me and ran off in his boss’s wake. So I left too, walking back to the village, where thousands of feet had churned the verges into mud. There was a sign over the road, hanging between two lampposts and dripping a little. It read, in Chechen: “Welcome, Honoured King, Ramzan, Son of Akhmad”.

• Follow the Long Read on Twitter at @gdnlongread, or sign up to the long read weekly email here.