One​ afternoon in Sanaa last November two lawyers in suits pushed, with purpose, through the doors of the Yemeni Tax Authority, a temple of nepotism and corruption. Several pairs of eyes followed them as they walked briskly down the corridors, the white walls rubbed into a grimy grey by the backs of those condemned to spend hours waiting in this purgatory of bureaucratic torment. People watched disbelievingly as the two men marched past the camouflage-clad armed guards into the office of the director himself. This was a place which no one could enter without the proper connections and/or a hefty bribe. The functionaries who tried to block the lawyers’ passage shrivelled and scuttled away when the younger of the two uttered the sacred words: ‘We are here on behalf of the legal wing of the Supreme Revolutionary Committee of Ansar Allah.’

Ansar Allah is the official name of the Houthis, the revolutionary movement which had recently taken over Sanaa, and the authority of the two lawyers emanated not from the single pistol they had between them but from the tens of thousands of militiamen who had entered the capital with them. The office with its massive glass-topped desk and leather sofas was rather different from the shabby corridors outside. The lawyers sat themselves down and the director offered them tea. A lackey tried to smooth the air.

‘We want the names of all big businessmen who aren’t paying their taxes,’ the younger lawyer said.

Sheepishly, the director tried to explain that he wasn’t actually in control of the tax office, that his employees were in reality there to serve the businessmen they were supposed to tax, that the tax authority wasn’t in the business of collecting taxes so much as involved in a game of negotiations between impoverished functionaries and the wealthy few until a bribe was paid and tax demands were reduced to a pittance.

The two lawyers looked bored. They had just come from a press conference at which they had declared that the Supreme Revolutionary Committee had exposed major graft and issued decrees confiscating the wealth of Hamid al-Ahmar, scion of the grandest tribal family in Yemen and a member of the Muslim Brotherhood, the Houthis’ ideological enemies. They were hungry for more ammunition to use against them. ‘We will examine all the files,’ the older lawyer said.

‘Let me tell you about another type of corruption. I uncovered it when I was head of the port customs department,’ the director said, trying to wriggle out. ‘It’s to do with bras.’

‘Bras?’

‘Yes, bras. Some are very expensive: luxury brands, not the usual red and pink you see in street stalls. But when they declare them they say they are cheap to avoid paying customs fees.’

‘We have other brothers whose job is to inspect shipments and customs. Can we see the files?’ the lawyer said. After another hour of negotiations, subtle threats and assurances of co-operation, they left, having secured an agreement that no forms would be signed – no tax declarations cleared, no decisions approved – without the permission of a representative of the Supreme Revolutionary Committee. The director and possibly the whole system would soon be rendered obsolete.

Early last year, the Houthis, followers of a revivalist anti-Western cleric, moved out of their northern highlands and marched south towards Sanaa, promising to end corruption, to fight al-Qaida, challenge US hegemony – al-Qaida and the Americans were allies in the subjugation of Muslims, they said – and raise Yemenis out of poverty and powerlessness into a shining and more dignified future. In 2011 President Saleh had been toppled to be replaced by his deputy, the aloof Abd Rabbuh Mansur Hadi, who had allowed al-Islah – the Yemeni branch of the Muslim Brotherhood – to control many offices of state. One crony kleptocratic elite had made way for another. Yemen wanted change and the Houthis faced little or no resistance.

The Houthis marched towards Sanaa slowly but with determination. They laid siege to sectarian rivals, fought tribal leaders aligned with those rivals and outmanoeuvred their own allies. Towns fell before their troops, army bases surrendered or switched allegiance without much of a fight and the houses of those who dared to oppose them were demolished with explosives. In mid-September they built protest camps around Sanaa, ostensibly to demonstrate against a planned hike on fuel prices but effectively laying siege to the city. The army did what it usually does and shot and killed several demonstrators. Two days later, on 21 September, after defeating tribal and military units affiliated with the Muslim Brotherhood, Sanaa went down without much of a crash or a thud. The UN special envoy and the president came up with an agreement that enshrined the Houthis as the new masters of the city, and to preserve the façade of the political process and safeguard their jobs they declared that in every other way it was business as usual.

With the help of Popular Committees, representing their military wing, the Houthis raided and blockaded ministries, scrutinised bank accounts and removed ministers and officials from office. They even confiscated that sacred sceptre of the state, the departmental rubber stamps. The state was held hostage. The Supreme Revolutionary Committee became the authority that wielded political power and was housed in the city centre in a white hotel building with square balconies and green stone cornicing. From the early hours of the morning until late at night a motley crowd came and went through its gates. They included farmers seeking to address injustices inflicted by wealthy landlords, tribal leaders pledging allegiance, maverick politicians seeking positions in the new administration or businessmen looking for ways to avoid punishment. Even tribesmen who had long bickered over blood feuds came seeking a solution. Everyone wanted absolution from the new rulers of Sanaa.

In the hotel’s neon-lit corridors, shoes and flip-flops were heaped outside rooms that were busy with debates and meetings. On the top floor, in a plain white room, sat the head of the Supreme Revolutionary Committee, Mohammed Ali al-Houthi, a cousin and brother-in-law of Abdul-Malik al-Houthi, the current overall leader of the movement. A big man with a permanent infant-like smile, he crouched cross-legged behind a low table, sifting through documents. A Kalashnikov rested against the wall next to him. He opened a plastic shopping bag, pulled out a thick pile of papers and started throwing them on the floor in front of him, like a dealer cutting a new set of cards. Each sheet represented a corruption case that was draining Yemen’s coffers and putting another burden on his shoulders.

One was a letter showing that a departmental head in the Ministry of Education had sold off some of his furniture for $435 to save costs and then awarded himself a bonus of $523. Another civil servant had misappropriated $2000 that was meant for schools. And then there was a gas and oil contract with the French company Total, worth $2.5 billion, that had been under investigation by the government long before the Houthis entered Sanaa. Everything had been gathered in the one plastic bag and now lay on the floor at his feet. ‘When we entered Sanaa, we never expected to be solving all these problems,’ Mohammed Ali told me. ‘There is an octopus of corruption in the ministries. It’s trying to prevent us from working. But we have an intelligence network that sends us reports of corruption from inside the ministries themselves. People come to us with their problems. We don’t charge anything: this is pure volunteer work. We want to solve problems quickly. Those who work in government want to delay in order to make money.’

He was one of the movement’s early members and had spent more than three years in prison. I asked him where a military commander had got the expertise to handle corruption cases. He smiled more broadly. ‘I was in the mountains and now I am here. We are simple people, how did we get this far?’ He marvelled at his movement’s achievement. ‘We don’t have big houses, we don’t have villas. We are poor people.’ He dismissed the UN sanctions against him personally and other senior Houthis, as well as the foreign embassies which had recently pulled out of Sanaa: they were mere gestures. ‘We aren’t worried about our bank accounts and resources. Let them impose sanctions. We don’t have bank accounts, we’re even banned from having ID cards. We live on the contributions of our members. If you are dependent on the outside for funding you will collapse. That is what happened to many revolutionary movements: you cut their support and they have to back down.’ A few weeks later, at the end of January, Mohammed Ali would become head of state and pictures of the shy, bulky man sitting in the president’s seat would spread on social media as the definitive sign of the Houthis’ takeover.

The Houthis emerged out of the teachings of Hussein al-Houthi, their eternal leader and martyr, killed in 2004. A dissident Zaidi scholar, orator and one-time member of parliament who came from a Hashemite family which claimed descent from the prophet Muhammad, Hussein had begun to deliver weekly lectures examining the problems facing the Islamic Ummah at the turn of the millennium. At the heart of these lectures lay the question that many Muslim scholars, philosophers, mullahs and millenarians had tried to answer for centuries before him: how can one reconcile the everyday reality of poverty, corruption and humiliation with the religious belief that God had designated the Arabs as his chosen nation and entrusted them to deliver Islam – the greatest and final religion – to the rest of humanity? Each sermon started with a long interpretation of a verse from the Quran, typically one exalting steadfastness and jihad. Then, in a neat twist of rhetoric, he would link the verse to current events – the visit of an official from the US State Department, the Americans’ illusory promises of development aid, the capitulation of Yemen’s government – before demanding reform not only of Yemeni society but of the Ummah as a whole.

The Houthis like to see themselves as a pan-sectarian, Islamic revolutionary movement but they are very much a product of the Zaidi religious tradition of Yemen with its emphasis on rebellion against the unjust ruler. Fundamentally part of the Shia school of thought, the Zaidis split, in the eighth century, from the main branch of Shia Islam when Zaid rebelled against the Umayyad ruler and rejected many of the teachings of the seventh Shia imam. In jurisprudence they are closer to Sunni Islam. Thus, the Houthis argue, Zaidism is the one sect in Islam that can claim to have one leg in each camp and to be a real platform for revolution. The Zaidis had to a large extent ruled Yemen for a millennium but by the time Hussein was growing up they were in retreat.

In 1962, nationalist and leftist army officers ushered Yemen into the modern age by toppling the last Zaidi imam, bringing an end to theocratic rule. Hashemite royalists and allied tribes, supported by the Saudis, fought a civil war against the republicans, backed by the Egyptians. After seven years of civil war, in which British mercenaries fought with the royalists, neither side could claim a complete victory: Nasser lost his army and the Saudis failed to bring a king back to his lost kingdom. As a child Hussein saw many of his relatives killed or imprisoned by republican forces. The Zaidi religious establishment retreated to the mountains of Saada province in the north. Those who wanted to study spent years there reading Zaidi religious texts in small groups with respected clerics, among them Hussein’s father. Zaidism clung on, but it had stagnated into a mummified version of itself. In the 1970s the Zaidi community came under a different form of attack, less violent but no less dangerous, this time from the Muslim Brotherhood and Wahhabi missionaries. Encouraged by Saudi money and the government in Sanaa, which saw the Brotherhood as a useful tool in fighting the communist threat, Sunni religious institutions began spreading in Yemen. Preachers were sent to Saada and surrounding areas and, with the appeal of Zaidism declining, many young people joined the Muslim Brotherhood.

But then came the Iranian Revolution. Some Zaidis, inspired, travelled to Iran, among them Mohammed Azzan, a progressive Zaidi scholar who now lives in a house in the hills overlooking Sanaa. ‘We admired the revolution,’ he told me, ‘regardless of our sectarian differences. I studied in the classes of Abbas al-Musawi, the founder of Hizbullah. He wanted us to abandon some of our beliefs but we didn’t.’ Hussein’s father went to Iran too, taking with him Hussein and his younger brother Abdul-Malik. They spent time in Qom, which shaped their revolutionary outlook. ‘When we returned from Iran,’ Azzan said, ‘we brought some Shia rituals back to Yemen. We were put in prison and accused of being Iran’s arm in Yemen. But it wasn’t true. The Iranians didn’t believe it, nor did most Yemenis.’ By now the Zaidi community was feeling stronger. ‘We formed two groups, one political and one cultural, and we managed to stop the Wahhabi expansion. There was suddenly an alternative for young people. We ran arts and sports programmes and brought the young people back. We started saying that the rebellion against the unjust ruler could happen constitutionally.’

Although Hussein al-Houthi ran for election and joined parliament in 1993 on the ticket of the mainstream Zaidi party, al-Haqq, he soon became disillusioned with the peaceful path. He believed that Yemeni politics was failing: parliament couldn’t rein in the corruption of the elite; most parliamentarians were cronies of the regime or influential tribal leaders. President Saleh was preparing the way for his son to succeed him; the system couldn’t be changed from within. ‘Hussein told me that you can’t change society with a cultural movement,’ Azzan said. ‘There had to be confrontation. You had to have an extremely radicalised group, built on revolutionary and military discipline, like the Taliban. And that’s when we split.’ The attacks of 11 September provided Hussein with the perfect pretext to raise his voice against the Yemeni government and he started giving his increasingly popular weekly lectures to farmers, traders and assorted villagers. Saleh, desperate to show that he was co-operating with the US in the war on terror, couldn’t allow a teacher from the provinces to embarrass him with anti-American rhetoric. The president ordered a crackdown, and hundreds of Zaidi religious activists were arrested. ‘In 2002,’ Azzan said, ‘we were two movements and the government didn’t distinguish between those who supported the Houthis and those who opposed them. Zaidis were targeted indiscriminately, and this state brutality pushed many to join the Houthis.’ In 2004 Saleh passed through Saada province on his way to Saudi Arabia and visited the Zaidis’ most sacred mosque for Friday prayers. As the imam finished reciting the final verse, young men rose from the crowd and started shouting Hussein’s slogan, inspired by the Iranian Revolution: death to America, death to Israel, victory to Islam. Saleh was humiliated and on his return ordered the army to deal once and for all with that troublesome preacher. The war that followed provided a nascent movement with its most valuable asset: a martyrdom legend.

Marran, where Hussein al-Houthi was born and where he died, is a stunning green valley, framed by the high peaks of dark blue and grey mountains which in the haze of early morning fade into two-dimensional cardboard cutouts against the rising sun. When I visited, houses on the hillside were awash in orange light and the terraces of qat and coffee cascaded into the shade of the valley below. High on the eastern side of the valley is a small cave entered through a narrow slit. It was here that Hussein and a handful of his followers were besieged, two months into the war, after most of his men had been killed, injured or had fled to safety. The army had occupied much of the valley with tanks and commando teams were dropped by helicopter into the places tanks couldn’t reach.

At the cave entrance were photographs of young men, buried where they fell. The cave has become a shrine to the legend of Hussein al-Houthi. A farmer who fought here with him appeared with a flask of coffee brewed from his fields, and started telling me about the last days of Hussein’s life. Hussein ran down the valley under tank fire to retrieve the body of a childhood friend, Zaid, and brought him back to safety. The army poured petrol into the cave and set it alight, cutting off one of their routes of escape. Hussein and his men ran out of food and got by on leaves and roots. My guide pointed at a peak where a sniper had been positioned, with a clear view of the cave’s only other exit. They were pinned down. Finally Hussein, injured, thirsty and surrounded, offered himself up in return for safe passage for his family.

The farmer stood on a ledge above a dizzying gorge next to the cave, and enacted the martyr’s last moments for me: Hussein, after surrendering, tried to grab the gun of the commanding officer; the officer executed him where he stood. The farmer finished his story, poured another round of coffee, stood up, picked up his flask and skipped up the mountain like a faun. He sat watching the cave waiting for the next visitor to arrive so he could repeat the legend of the last days of Hussein al-Houthi, with its remarkable resemblance to that of Imam Husayn, another descendant of the prophet who tried to rebel against aggression.

In Sa’dah City, the regional capital, it’s hard to find out much about Hussein the man. He has been replaced by a stencilled picture of the ‘martyr-commander’, his thick beard, deep-set eyes and square glasses somehow making him look more like a Hizbullah commander than the Yemeni he was. He stares down from the walls of buildings, from lampposts and banners, and from the blue plastic sheets, arranged like Persian tiles, which cover the walls of the tomb in Marran in which his remains were reinterred in 2013. People who knew him when he was young couldn’t remember or wouldn’t tell me how he sat or how he ate or if he laughed or made jokes: they speak of him with reverence as if of a prophet or god-king.

The Houthis’ supreme military commander, Abu Ali al-Hakem, is a delicate and compact man, one of the original 75 who fought alongside Hussein in the first battle in the mountains of Marran and one of the few who survived. In Sanaa one evening I watched him enter the Houthis’ headquarters accompanied by two gunmen; his arrival caused a flutter among even the most senior apparatchiks. He wore a dark blue coat over a crisp white dishdasha, with a leather pistol holster strapped to his chest. He spoke of his memories of the war, of a day of heavy battle, it was the third or fourth war, he couldn’t remember. The Houthis had lost many men and they were besieged. ‘At dawn the fighting stopped and I decided to take a break. I switched on the TV. I wanted to see what the world was saying about us: the whole world would be speaking of this battle. I flipped through the channels. There was nothing, even from countries we call our friends, nothing in Iranian or Arabic. There was no mention of us. We were alone and there was no one to help us.’ He spoke in the language of good and evil. ‘How can we not win if we have God with us?’ The Houthis – from Abu Ali al-Hakem to the lowliest fighter – all spoke in the same terms, a logic developed after a decade of war and siege in the mountains. They were the pure and all their enemies or those who raised their voice to oppose them – leftists, the media, the Muslim Brotherhood, jihadis – were all Daesh, or Isis, or agents of the US and the Saudis. Their enemies in turn portrayed them as an Iranian militia, alongside those of Bashar al-Assad and the Sadrists in Iraq.

In January, President Hadi resigned, having in a rare act of defiance refused an order from the Supreme Revolutionary Committee to appoint a deputy – an act which surely would have rendered him disposable. He was placed under house arrest and the Popular Committees started to take a closer interest in activity on the streets of Sanaa. Pictures of Hussein al-Houthi were stencilled onto brick walls in narrow lanes, and his slogan was printed on cardboard signs at checkpoints manned by teenage boys, declaring, in green and red, the greatness of God, death to America and Israel, and proclaiming the victory of Islam. On the main thoroughfare, hung from billboards in shades of green, were the proclamations of Abdul-Malik al-Houthi, Hussein’s brother, urging his followers to bring an end to US hegemony and to boycott US and Israeli goods. An intelligence unit the Houthis had developed during the war had now expanded its activities and was kidnapping activists and journalists. Demonstrations were quelled with live ammunition and the investigations into state corruption were becoming a tool that targeted the Houthis’ enemies only. Sunni mosques were turned into Zaidi mosques, revenge for what the Wahhabis had done decades ago. Muslim Brotherhood activists were arrested and then the whole party was dissolved. Even Mohammed Azzan, the non-Houthi Zaidi scholar, had his mosque confiscated. All the committees and revolutionary rhetoric, more befitting a Marxist organisation than one deep in religious dogma, couldn’t disguise the fact that this was a sectarian militia involved in a power grab that was pushing Yemen towards civil war.

I went to meet the man who was officially still Yemen’s prime minister, Khaled Bahah. He too was also under house arrest, along with his cabinet. ‘What have the Houthis achieved?’ he asked. ‘They came to fight corruption. They may have saved a few million riyals but the economy has lost billions. They came to fight al-Qaida and now we have Isis.’ The Houthis’ takeover was complete, but it was becoming clear that it had less to do with divine intervention than with the machinations of Yemen’s old dictator. Saleh was spending his days in a gazebo in his garden, meeting delegations of loyalists who were plotting and campaigning for a return if not for him then for his son, pictures of whom, wearing Ray-Bans, were being sold in the streets along with those of Abdul-Malik al-Houthi. ‘I am just a Yemeni interested in politics and they can’t stop me in that,’ Saleh said, his voice slightly slurring and his hands still bearing the scars from a bomb attack a few years ago. ‘The Muslim Brotherhood and the al-Ahmar family insulted the tribal leaders, so when the Houthis started marching the tribes showed them the way to Sanaa.’ But the tribal sheikhs, along with army officers predominantly from the Zaidi north, did more than give the Houthis street directions. Their influence and privilege had been severely curtailed after Saleh’s departure, and they saw the Houthis as a way of redressing the balance. ‘After 2011 we were almost wiped out,’ a senior member of Saleh’s party told me. ‘The behaviour of the Muslim Brotherhood united many people in opposition. In 2012 we struck a deal with the Houthis: we wanted to topple the current administration. But they wanted more. They took away the state we saw as ours.’

At the end of February, President Hadi escaped house arrest and fled to Aden, where he retracted his resignation and declared the Houthis’ administration illegitimate. Then the real war began. The Houthis started moving south and east and Aden came under siege. Hadi fled the country and resurfaced in Riyadh; the Saudis started their bombing campaign. According to UN figures, between the end of March and the beginning of May, 646 Yemeni civilians have been killed and more than 1300 injured in the airstrikes. ‘The Houthis lost a historic opportunity when they moved beyond Sanaa,’ one of the few tribesmen who still meets regularly with Abdul-Malik told me. ‘People were hungry for stability and reform. Had he stayed in Sanaa and actually fixed the system they would have become popular everywhere.’ But as it is Yemen is being held hostage by opposing forces: on the one hand, a militia determined to fulfil the divine victories promised by a dead leader; on the other a hubristic Saudi kingdom, with US backing, intent on destroying another country in its quixotic sectarian war against Iran.