One by one, the priest anointed the rebel recruits with holy water. In the dilapidated grounds of the front-line church, each fighter knelt to kiss a Bible, a portrait of the Virgin Mary, the billowing flag of the Great Don Army, and an antique saber, touching their lips to its curved blade.

This final ritual closed the solemn, hourlong ceremony. The ragtag band of rebels now stood as Cossacks.

The church lay in the outskirts of Pervomaisk — a wretched corpse of a town, ruined by months of frontline fighting in Ukraine's far eastern frontier. Many of the 130 men and women assembled there had already seen action. Some had fought in the ferocious battle for Debaltseve, in the Donetsk province, in February; others would be returning to the trenches just a few miles north within hours.

But the rite was necessary to mark their formal initiation into the warrior caste.

Since the early months of war last year, the self-proclaimed Luhansk People's Republic (LPR) has been plagued by splintered loyalties and rival factions as the battle against the Kiev government was subcontracted to an irregular coalition of local warlords, foreign mercenaries, and political extremists.

Don Cossacks have been among the most outspoken militias in their opposition to the ruling rebel authorities. Earlier this year, LPR chief Igor Plotnitsky set a deadline to quash the enemy within and consolidate the centralized power of his breakaway enclave. He told the Cossacks that they had until April 4 either to join the new republic's military, to surrender their weapons, or to face arrest.

Three months after that ultimatum, VICE News traveled into the war-torn, rebel-held territory to see what had changed. On paper, the Don Cossacks serve the wider LPR army. But tensions remain high. The initiation ceremony highlighted the group's persistent determination to fight for their own cause.

Photo by Pierre Crom

Photo by Pierre Crom

On the road from the separatist stronghold of Luhansk earlier that morning, our government minder cranked up California Dreamin' on the car stereo as we sped past endless ochre fields. "We register with the local division, then set off to the front! We have monsters to kill!" he shouted in jest, eyes glinting.

Forty miles later, a handful of well-armed soldiers checked our documents at a roadblock and called in a military escort. We headed into Pervomaisk in a convoy, led by a rebel in a yellow Lada. The vast steppe buckled into a valley as the minder put on Orthodox Serbian choral music and yelled over it, "Welcome to hell, boys! This is Ukrainian Kosovo."

The comparison was tenuous. The Ukrainian army's activities do not compare to the atrocities of the Serbian war machine. But the rolling landscape was certainly more Balkan vale than Eurasian steppe. And as we neared the church where the initiation ceremony was to be held, the gravity and headiness of the Orthodox religion pressed down hard upon the rebel-held town.

A martial people, romanticized as outlaws and renowned for their battlefield prowess, the Cossacks have participated in just about every Russian conflict in modern times. While the exact origins of this quasi-ethnic group are disputed, it has a strong tradition of independence, counting among its ranks peasants who had fled a miserable life of serfdom in Lithuania, Muscovy, and Poland. They lived as free men in the lands stretching from Siberia to Ukraine's Donbass, drawing on their skills as horsemen and soldiers to patrol the frontiers of Imperial Russia.

There are the Zaporizhian Cossacks of central Ukraine, who launched a powerful but ill-fated independence movement in the 17th century before being crushed by Catherine the Great; they have since been rebuilt as a pillar of Ukrainian nationalist sentiment. But the Cossacks in the Luhansk region, originally from Russia's neighboring Don province, are a separate branch. Along with the Kuban, the Volga, Terek, and so on, they are reactionary and often fiercely pro-Russian.

Regarded by Soviet authorities as unwanted relics of the tsarist era, Cossack officers were killed and imprisoned by the thousands. But a state-sponsored revival followed the collapse of the USSR. Armed Cossack militias fought alongside the Russian army during its invasion of Georgia in 2008 and annexation of Crimea last year. Thousands more have funneled across the border since the outbreak of the Ukrainian war to join the separatists and form militarized, Orthodox battalions. They blindly claim to be defending their Slavic lands against an army they brand as fascist invaders from Kiev.

In contrast to the elite reputation of their forebears, scores of recruits milled around the car park outside Pervomaisk's church, smoking, joking around, and posing for pictures. Most were men in their early 20s to late 40s; a handful were women.

All wore the traditional fur hats, topped with red and marked with a white cross. Many claimed to be in some way related to the Don Cossacks. The rest were just in it for the ride.

Photo by Pierre Crom

Among the crowd stood Sergey Zagoryliko, a Russian Army veteran of the 1992-93 separatist war in Abkhazia. The sides of his head were cropped short, his magnificent, 10-inch moustache on full display. His fighting days were behind him, he said, and he had journeyed from his Cossack village in southwestern Russia to witness the ceremony.

"This conflict is taking place within the same family. It is brother against brother," Zagoryliko, a 10th generation Kuban Cossack, told VICE News. "The devil lingers between the same people.

'Today is the official start, but we felt like Cossacks before. It was passed to us in our mother's milk'

"I'm not here to fight. I will just support these Cossacks today and return home. For these men and women, this initiation is their destiny."

An order was barked out and the recruits formed a long line facing the church, dedicated to St Paul and St Peter. Pavel Dremov — their ataman, or leader — strutted before them. A thorn in the side of the LPR, the former bricklayer has accused the regime of presiding over a kleptocracy that diverts humanitarian aid to the black market.

"You will serve the people!" Dremov commanded, reasserting the group's fundamental rejection of the state. "You will not serve politicians! You will not serve presidents!" In a chorus befitting a cohort of Hollywood Spartans, they shouted back in consent with one voice, "Luba! Luba! Luba!"

Sergey Zagoryliko. Photo by Jack Losh

In their varying shades of camouflage, they marched into the churchyard to commence the prisyaga, the swearing-in ceremony. A duet of women sang Orthodox hymns a cappella before the priest addressed each fighter by the ancient Slavic versions of their names. "You swear to yourself and to God to defend the fatherland and live by the Bible," he intoned.

They repeated an oath that shone a spotlight onto their deeply held rejection of any republic other than their own. "I swear to the Order of the Cossacks, in the presence of God and the Orthodox religion, to serve the Great Don Army and bring glory to the ataman," they chanted in unison. "I swear to fight to the last drop of my blood for my own glory and for the strength of the army. I swear to fight for the Cossack homeland, not for the politicians."

"It was like a baptism," one Cossack told VICE News afterward. "I will fight shoulder to shoulder with these men. Not one of my brothers recognizes the authority of the LPR."

Another fighter and an unlikely Cossack hopeful, Evgeny Zhenia, 29, a divorced man from Magadan in Russia's far east, said, "I received the spirit of safety. My brothers and I are now protected. Our family has become bigger and better.

"Today is the official start, but we felt like Cossacks before — that same feeling brought us to war. It was passed to us in our mother's milk.

"We fight for freedom, for the people. We fight for no politician — not for Putin, not for Plotnitsky, not for any ideology."

Stas Chisayko, 25, had joined the Ukrainian army in 2012 before switching sides this year. "Now my only allegiance is with the Cossacks and the ataman."

Tensions on both sides are far from defused. Following Plotnitsky's deadline for Cossacks to swear primary allegiance to the LPR, "hundreds" of Cossack fighters were arrested, according to a regime source. Some have been released and stripped of their weapons, while others remain in jail, the source added.

Renegade Cossacks are a major headache for other rebel groups. Alexei Markov, deputy commander of the Ghost Brigade, a pro-Russian separatist brigade in nearby Alchevsk, was scathing of his new allies. "They are volatile and unpredictable," he told VICE News. "That traditional Cossack bravery…" He flicks his index finger against his throat, the local gesture for boozing.

"At Debaltseve, my first battle was not with the Ukrainians but the Cossacks. They shelled us with friendly fire. I had to move my entire unit through no-man's land, past mines and traps. When we met up later, they refused to apologize.

"Lines of communications are open with Dremov [the local Cossack leader]. He takes care of his fighters and keeps order. But he's a very difficult man to deal with.

"There are still many Cossacks who don't obey LPR."

Photo by Pierre Crom

After the ceremony had ended, the Cossacks dispersed in troop carriers and battered sedans. We passed through the center of Pervomaisk. This desolate, forgotten town had borne the brunt of catastrophic artillery barrages last winter during the Ukrainian army's failed bid to dislodge separatist troops.

Half its population was forced to flee while the rest endured the winter. Hundreds of civilians died.

Block upon block lay devastated. Windows remained shattered and glass crunched underfoot. Empty shell cases piled beneath a statue of Lenin. The skeleton of a bombed-out bathroom was exposed, toiletries neatly lined up on a shelf by some dark jokester.

On the road to Luhansk, the urban devastation gave way to a vista of rolling grassland. "I am fond of Hindu philosophy," the government minder said, addressing no one in particular as the rest of us sat in silence.

"People here only see things in terms of good and bad. But the Hindus have one more. There is Sattva, the good. Tama, the bad. And Raja — passion. The last one is like fire or lava or a volcano. It can't be determined good or bad. It just is.

"I can't live in this conflict like a Zen monk and look at everything I see, saying, 'This is bullet, this is soldier, this is tank.' It all has an effect on me. Raja helps me stay neutral. For me, war is raja."