When British soldiers were sent to Russia after the Russian Revolution their main enemies were the Germans - their opponents in World War One - but they also found themselves fighting and imprisoning Bolsheviks. In the process they opened what Russians regard as the first concentration camp in their country.
The boat sails down the River Dvina past onion-domed churches, lumber yards and logs floating in the water. Finally it reaches the open sea and an hour later a brown smudge appears on the horizon.
Getting closer, I can make out a lighthouse and a few radio towers. As my companions and I jump off the boat and walk along a deserted beach a pack of dogs surrounds us, barking furiously. They are not used to visitors. The only people who live on this remote spot today are border guards and a couple of meteorologists.
Back in the Soviet era, boatloads of day trippers came to the island of Mudyug to visit a museum. It was located among the remains of a prison camp - one very different from the scores of old Gulag outposts scattered across the Russian north and Siberia. For one thing, it was set up as far back as 1918. Even more remarkably, the people in charge were were British and French.
My colleague Natalia Golysheva, who grew up in the regional capital, Arkhangelsk - Archangel as it used to be known in English - says the place had a fearsome reputation. Locals called it Death Island.
"When I was little, people said if you don't behave, the Whites will come and take you to Mudyug," she says. "I didn't understand but when I tried to ask questions - 'What is Mudyug? Who are the Whites?' - my grandmother just said shush and turned her face away, meaning the conversation was over."
The Whites were the anti-Bolshevik forces that emerged after the October Revolution in 1917. They got the name from the cream-coloured uniforms worn by higher ranks in the Tsarist army. Some were reactionary military officers who wanted to bring back the monarchy, others were moderate socialists, reformers, tradesmen, fishermen or peasants.
When the Bolsheviks seized power in the autumn of 1917, Russia was still fighting in World War One, allied with Britain, France and the US against the Central Powers of Germany and Austria-Hungary and their Ottoman allies.
However, Lenin had come to power promising supporters not only bread to eat and a share of the aristocrats' land, but also peace. When he signed a peace treaty with Germany, Western governments acted rapidly to re-open this eastern front.
Within months, tens of thousands of soldiers from Britain, the United States, France, Canada, Australia and other countries were ordered to Russia in what became known as the Allied Intervention. Some went to the south and far east of Russia and 14,000 troops under British command were sent to Arkhangelsk, near the Arctic Circle. The men were told their mission was to protect military stores and stop Germany from establishing a submarine base.
But the foreign troops also took the side of the Whites in Russia's nascent Civil War. Some European politicians, such as Winston Churchill, worried about Communism spreading across Europe.
Soon after the Allies docked in Arkhangelsk on 2 August 1918, they began locking people up. "They didn't know who to trust or the difference between the Reds and Whites - so they decided to incarcerate anyone who seemed suspect," says Liudmila Novikova, a Moscow-based historian who has become an expert on the post-revolutionary period in the Russian north.
Since the main prison in the town was overcrowded, potential troublemakers were shipped to the island of Mudyug, 70km (45 miles) away. The first batch of inmates had to build their own prison camp in this desolate, windswept place.
We walk along the beach past a rickety watchtower before taking a path through a pine forest. It leads to some wooden barracks with rusty barbed wire on the windows.
The door opens with a creak and we are inside a long dormitory with hundreds of beds, divided by panels of wood. Each seems as narrow as a coffin.
Marina Titova, a young museum guide from Arkhangelsk who has joined us on the trip, sits on one of the beds, lost in thought.
Her great-great-uncle Fyodor Oparin, a roofer, had been at the front fighting the Germans in World War One. He was only briefly reunited with his wife and small daughter before he was arrested and sent to Mudyug, accused of recruiting the men in his village into the Red Army.
With few washing facilities and no change of clothes, inmates soon became infested with lice. Typhus spread like wildfire. Overall, about 1,000 people were imprisoned here and up to 300 died - either as a result of disease, or because they were shot or tortured to death.
When we visit it is a muggy summer afternoon and the air is thick with midges. I dread to think what it would be like here during an Arctic winter when temperatures can reach -30C (-22F). Signs from the now abandoned museum point out the "ice cells", left open to the elements, where rebellious prisoners were punished and either perished or lost limbs to frostbite.
Pavel Rasskazov, a radical journalist, spent several months on Mudyug. In his Prison Memoirs, which became a well-known and much-studied text in the Soviet era, he documented the appalling conditions and the lack of food.
He describes how, when dried bread was distributed in the morning, "starving, angry men with greedy eyes crawled all over the filthy, damp floor, full of spit, picking up each and every crumb".
Rasskazov managed to survive this place, unlike Marina's relative, Fyodor Oparin. According to one account, he tried to escape but was too weak to move fast and was shot as he ran. In another version of events, he was caught and executed the following day, along with 13 other prisoners.
Under some fir trees Marina has found a commemorative plaque to the men killed trying to escape. As she places two red carnations on the crumbling stone, a cloud of mist swirls through the trees and a soft rain falls.
"Perhaps it was just a coincidence," she says later. "But it seemed like a greeting from the past, and maybe those prisoners who suffered here, who tried to survive, could see that they were being remembered."
In Soviet times these men were remembered more often. On a small hill by the camp, there is a 25m-high obelisk adorned with a red star and hammer and sickle. Some chunks of granite have fallen off but you can still read the inscription which says it was built "in honour of patriots tortured to death by the Interventionists".
"This monument could be seen by all the ships sailing past," says historian Liudmila Novikova. "Foreign sailors who came to Arkhangelsk were often taken to Mudyug to remind them of all the atrocities their fellow countrymen and governments committed here."
Schoolchildren and factory workers also came on visits.
Near the monument, we find a run-down hall with dusty glass cases, peeling red posters on the walls and photographs of the "martyrs who gave their lives for the Revolution" or died here on the island, which is described in the inscriptions as a concentration camp.
There are pictures of Gen Edmund Ironside, the British commander of all the Allied troops in the region. Novikova says he would have known what was happening on the island even if he never visited.
This is confirmed by an entry in the leather-bound notebooks he kept in Russia, now in the possession of his 93-year-old son.
"Scurvy seems to be beginning among the Russian prisoners on Mudyug Island… and as it is a difficult place to get to, rations have been pinched," the general writes.
If the British established the camp and some of those in charge were French, many guards seem to have been local men. "We cannot have a scandalous camp," he writes. "I am responsible that the Russians treat their people well. I am always after them over the state of the prison."
But Novikova says improving conditions on Mudyug was hardly a priority for Ironside. "For him it was just a necessary security measure, and after all people were fighting and dying every day on all the fronts. So if prisoners in the rear were dying from bad conditions, that was just a drop in the ocean of suffering here."
The treatment of prisoners on Mudyug horrified one man who would later play a devastating role in northern Russia. A prominent Bolshevik close to Lenin, Mikhail Kedrov, was sent to Arkhangelsk after the October revolution and later became became a fanatical regional head of the Cheka - the secret police.
Alexander Orlov, a fellow Chekist who later defected to Canada, recalls Kedrov as a tall handsome man with ragged black hair. He writes that his eyes were often "gleaming like burning coal… possibly these were the sparks of madness".
While the Red Terror was not mentioned in the USSR for decades, the crimes of the White forces were endlessly listed in official propaganda. Atrocities were committed on both sides, says historian Liudmila Novikova, but the scale was different.
"The Whites and Allies who supported them were mainly pragmatic. They wanted to kill those who undermined their effort, troops who rebelled or members of the Bolshevik underground - they didn't care about eliminating their enemies totally. It was quite different on Red side because they were waging a war against the old regime - the bourgeoisie, Tsarist officers and whole classes were perceived as enemies who had to be liquidated," she says.
Find out more
Lucy Ash tells the story of the forgotten war fought by Western troops in Arctic Russia in The Red and the White, on the BBC World Service
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Mikhail Kedrov set up a number of death camps in the North, including the first one of its kind, in Kholmogory, an hour's drive from Arkhangelsk.
Somewhere between 3,000 and 8,000 people were imprisoned and killed at a 17th Century convent. Many were White Army officers and sailors from the Kronstadt naval fortress near Finland who had rebelled against the Bolsheviks. But others had nothing to do with the military. Some were clergy, some were ordinary people who for some reason had been labelled "counter-revolutionaries".
At Kholmogory, where much of the convent is now held up by scaffolding and wrapped in corrugated iron, I met Elena, a parishioner who sings in the convent choir. She says people in the area sometimes find skulls when they dig pits to store potatoes over the winter.
Elena says the priest and volunteers collected some human remains in sacks and buried them under a marble cross on one side of the Cathedral of the Transfiguration. Each year they sing a requiem for those who died.
It's hard to pinpoint but there is an oppressive atmosphere which clings to this place, like the cold to the refectory walls when Elena invites us inside for a cup of tea.
Locals use the path through the garden as a shortcut across the town but Elena says few know - or care - about Kholmogory's terrible history.
Does she believe the Allied Intervention was the catalyst for Russia's devastating civil war, as Lenin and others have often claimed?
"I remember in my childhood hearing stories from my granny," she says. "I was a Young Pioneer and I told her the Reds were good and the Whites were bad and the Intervention troops were bad. And my granny said 'What are you talking about? The English came to our village, they brought us white flour, they gave the children sweets.' And I said: 'Granny - that is impossible they are our enemies!'"
Elena shakes her head. "They were not our enemies and to say they were responsible for the civil war is wrong. Of course not! We had enough of our own scoundrels without the intervention troops."
Mudyug and Chanel
The radical journalist, Pavel Rasskazov, who documented his ordeal on Mudyug island, describes a French-Russian officer and former businessman from Moscow, a man "of medium height, stout, with a round, flabby face, like a bulldog".
Ernest Beaux was actually a perfumer who concocted scents for the tsar's family - such as the "Bouquet de Napoleon". But in 1918 he was working as a counter-intelligence officer on Mudyug, interrogating Bolsheviks captured by the White Russian and Allied armies.
By the end of the year, Beaux had emigrated to France, where a cousin of Nicholas II introduced him to the couturier, Coco Chanel. He has gone down in history as the man who invented Chanel No5. According to some accounts he wanted to capture the essence of snow melting on black earth and as inspired by his time in the "land of the midnight sun" - the Russian Arctic.
Additional reporting by Natalia Golysheva