Czar Nicholas II
Tsar Nicholas II of Russia was an autocrat until 1917 when he was forced to abdicate the throne during the Russian Revolution.
The tsars had enjoyed unlimited power in Russia. Only Nicholas II had to deal with a revolution, which forced him to abdicate.
Most people call it the Russian Revolution-- maybe there is a less obvious name for it. The February Revolution of 1917 is the one which forced the Czar to abdicate. It is also sometimes called the Patriotic Revolution. The October, or Bolshevik Revolution, is the one which overthrew the Provisional Government which replaced the Tsar upon his abdication.
Alexander Kerensky was the Russian Prime Minister who was forced to resign as a result of the Russian Revolution (and who died in exile). Czar Nicholas II had already abdicated, prior to the revolution (but was executed anyway by the vengeful Bolsheviks).
The Tsar (or czar) Nicholas II.
The equivalent in history is when the Bolsheviks forced the Czar to abdicate his throne.
The February Revolution of 1917
Because he was forced to abdicate by the "July Revolution" of 1830.
There were industrial riots in Saint Petersburg which the army was unwilling and partly also unable to put down. The Russian Parliament took over the government and the Tsar was forced to abdicate. At this point the Communists did not take over; that was to happen later, in the 1917 October revolution.
There were two Revolutions in Russia. In the March Revolution, anti-czarists forced teh czar to abdicate and set up a democratic government. In the November or Bolshevik Revolution, the Bolsheviks (communist party) overthrew that government and turned Russia communist.
Because he had no other choice but to fight back
It was the German Revolution that forced Kaiser Wilhelm II to abdicate his imperial crown in 1919. The German Revolution began in 1918, and ended 9 months later in 1919.