More than cousins, the pair were good friends, so why didn't the British ruler act?
Pictured arm in arm wearing yachting uniforms, the two future kings could be mistaken for twins. But while cousins Tsar Nicholas II of Russia and Britain's King George V were described as close friends, their relationship ended in ruthless circumstances.
As head of an empire that was waning, where many citizens experienced extreme poverty and autocratic rule, Nicholas II found himself caught between a world war and the discontent of his own people. The explosive mix would hasten his fall from monarch to executed prisoner in just over a year.
The killing of Nicholas II, tsar from 1894 until his forced abdication in 1917, saw the collapse of Russia's royal family. His grisly death in 1918 and the murder of the Romanov family by a Bolshevik firing squad at a house in Ekaterinburg also placed George V's reputation under scrutiny.
Numerous archive images show the two kings from across Europe together. Some of the most striking photos are of the pair dressed in near-matching sailing attire and posing for what appears to be a royal portrait.
The pictures hint at a close bond, which makes suggestions that Nicholas II's relatives in Britain refused or were passive in trying to save him all the more intriguing. Did the king of England sell the tsar and his family down the river to preserve his own power base, or was he put under pressure by a government to ignore an SOS in the midst of the more pressing matter of fighting World War I?
Initially, the government that deposed the tsar was open to his leaving the country alive. However, their Bolshevik successors were less interested in facilitating safe passage. The British government apparently had designs on allowing the stricken tsar to gain asylum from a rising underclass and a Bolshevik Party which wanted his family eradicated. But help never arrived and Nicholas II spent his last days as a captive, first in Tobolsk and then in a city east of the Ural mountains. It was in Ekaterinburg that the tsar, his wife Alexandra and their five children were gunned down.
BBC Royal Biographer Theo Aronson wrote how Nicholas II's death was the price for preserving George V's position on the throne, given fears that the tsar's poor reputation as a monarch could spark a similar worker uprising in Britain.
"[George V] realised that, to most of his subjects, the tsar was a bloodstained tyrant... that this was no time for a constitutional monarch, apprehensive of his own position, to be extending the hand of friendship to an autocrat - however closely related. So the Russian imperial family was left to its fate," Aronson said.
Historian Catherine Merridale, author of Lenin on the Train, refers to an offer of asylum being withdrawn on "personal and diplomatic grounds." She states that Sir George Buchanan, the British ambassador to Russia, had initially brokered a passage to Britain, only for it to fall through.
Meanwhile, Prince Michael of Kent, the Queen of England's cousin, claimed in a 2010 interview that despite, Britain turning down an asylum request for the tsar, George V held out hope he could rescue his relative. "They were very close," he said of the monarchs' relationship.
Ultimately, no rescue came from the tsar's British cousin, and the lives of the Russian ruler, his wife and his children came to a brutal end in an Ekaterinburg basement, with their bodies hidden in unmarked graves outside the city for decades to come.
To learn more about the Russian Revolution, check out the hashtag 1917LIVE on Twitter. RT has been running a huge historical re-enactment with dozens of characters, including Vladimir Lenin and Nicholas II, tweeting as though the social media platform had been available to them at that time. The main anchor of the project is the Twitter account of the Russian Telegraph, a fictional newspaper breaking the latest news of 1917 and retweeting the key historical figures taking part in the project.ass