The Tsar
Since his abdication in 1917 in the wake of the February Revolution, Tsar Nicholas II had been under house arrest with his family. Negotiations for asylum in the United Kingdom and elsewhere continued as the family were moved from Petrograd in the summer of 1917 to Tobolsk, and then in the spring of 1918 to their final destination of Ekaterinburg.
Nicholas II had initially abdicated in favour of his son but then altered his choice to nominate his own brother, Michael. The latter accepted on the condition of the proper formation of the Constituent Assembly; the condition was never realised. The presence of Nicholas II and his family in Russia in the wake of the October Revolution was a huge concern for the Soviets. Sending them abroad would allow them to garner support for the anti-revolution movement. Keeping them in the country required regular moves as the civil war’s fronts shifted back and forth. By this point of 1918, their execution was almost inevitable.
Sbornik statei posviashchennykh pamiati Imperatora Nikolaia II i ego semʹi (1930) 586:8.c.90.138