Alexander II of Russia

Alexander II (29 April 1818 – 13 March 1881), also known as Alexander the Liberator, was the Emperor of the Russian Empire from 3 March 1855 until his assassination in 1881. He was also the King of Poland and the Grand Duke of Finland. Secretly, he was an ally of the Templar Order.

Eventually, the Tsar's promises began to fall flat, and so a group of revolutionaries in Russia, known as the People's Will, began plotting Alexander's murder. After numerous failed attempts, the Assassins, led by Sofia Perovskya, killed Alexander in a bomb attack on the imperial carriage in Saint Petersburg in 1881.

Source

 * Assassin's Creed: The Fall