The message could hardly have been more explicit. "Events last week have deeply distressed me," George V wrote to his cousin Nicky in March 1917. "My thoughts are constantly with you and I shall always remain your true and devoted friend, as you know I have been in the past." But it was never delivered. Only days earlier, Nicholas II, emperor of all the Russias, had abdicated his throne and, amid the surge of revolutionary sentiment, the new provisional government's foreign minister, Pavel Milyukov, warned that he could never receive it.

But as demand for the Romanovs' execution swelled, Milyukov began to wonder whether they wouldn't be better off if they were outside Russia. On 21 March, he asked the British ambassador if they could be offered asylum. It was one of the most fateful requests in our history.

Frigate to the rescue

Although the Romanovs' arrival in Britain seems inevitable now, it might never have come to pass. Even as Nicholas - by this time under house arrest at his palace in Petrograd - was making packing lists for the journey west, and even as his wife, Alix, was remembering her holidays with Queen Victoria, Cousin George was getting cold feet.

By early April, his private secretary recorded that the king was receiving "letters from people in all classes of life . . . saying how much the matter is being discussed, not only in clubs but by working men, and that Labour members of the House of Commons [were] expressing adverse opinions of the proposal".

Was George going to withdraw his invitation? It looked like it. But then, while he was going through his stamp albums one morning, a photo fell out. It showed the two cousins George and Nicky, side by side at the wedding of the kaiser's daughter in 1913. Tears sprang to George's eyes; all his doubts fell away.

Getting the Romanovs out of Russia was one of history's great secret operations, later immortalised in Roger Moore's film Russian Getaway. The task fell to military intelligence, known then as MI1. In May 1918, five British agents stormed the house in Ekaterinburg where the Bolsheviks were holding the royal family. Two agents were killed, but the others managed to get the Romanovs into the waiting getaway cars. They headed north to Murmansk, occupied by Allied and White Russian forces, where a Royal Navy frigate was waiting. Two weeks later, Nicholas II walked into the great hall at Sandringham to greet his cousin. He tried to speak, but there were no words. A moment later, he was weeping.

At first, George's misgivings seemed to have been groundless. After he changed the royal family's name from Saxe-Coburg-Gotha to Windsor, there was a surge of patriotic support for the monarchy, and when the Romanovs took their first steps in public, strolling along the seafront at Bognor, there were cheers from the watching crowd. But once the war was over, public disillusionment began to set in. Amid the intense labour unrest of the early 1920s, the Romanovs became a popular target for socialist agitators, encouraged by Grigory Zinoviev's new Comintern. In 1921, Nicky and Alix were jostled by demonstrators while leaving the London premiere of Charlie Chaplin's The Kid. A year later, their youngest daughter, Anastasia, was kidnapped by Irish republicans and released only after Lloyd George's government secretly paid a huge ransom. Admitting the Russians, the PM said glumly, was "the worst decision" he had ever made.

Bombed out

Under other circumstances, perhaps the General Strike of 1926 would have passed off differently. But when, on 6 May, a bomb exploded outside the Romanovs' house on the Sandringham estate, an angry mob besieged the Soviet embassy in London. By the following morning, small patrols of British Fascists, who had already distributed anti-strike propaganda, were roam­ing the streets looking for strikers and socialists. When another bomb exploded at the Café Royal two nights later, the new prime minister, Stanley Baldwin, came close to collapse. The strikers gave way, but Baldwin's health was broken, and by the summer he was gone.

The rest is history, from the succession of the hardliner Winston Churchill and the formation of the national government to the anti-communist alliance with Italy and the second Allied intervention in Soviet Russia. It is odd now to reflect that, if only George V had not seen that photograph, it could all have been so different.