The Romanovs isolated in Crimea knew little of the fate of the Tsar and his family. Nicholas, Alexandra, and their children, were originally held at their official residence, the Alexander Palace, but the Provisional government under Alexander Kerensky relocated them to Tobolsk, Siberia. In February 1918, most of the imperial family at Ay-Todor was moved to another estate at Djulber, where Grand Dukes Nicholas and Peter were already under house arrest. Olga and her husband were left at Ay-Todor. The entire Romanov family in Crimea was condemned to death by the Yalta revolutionary council, but the executions were delayed by political rivalry between the Yalta and Sevastopol Soviets. By March 1918, the Central Power of Germany had advanced on Crimea, and the revolutionary guards were replaced by German ones. In November 1918, the German forces were informed that their nation had lost the war, and they evacuated homewards. Allied forces took over the Crimean ports, in support of the loyalist White Army, which allowed the surviving members of the Romanov family time to escape abroad. The Dowager Empress and, at her insistence, most of her family and friends were evacuated by the British warship HMS "Marlborough". Nicholas II had already been shot dead and the family assumed, correctly, that his wife and children had also been killed.