The assassination of the Czar and his family in 1918 was a result of many factors, chief among them being political unrest within Russia. The Bolshevik Revolution had recently taken place, and sections of the Russian population were unhappy with their new government. They looked to the powerful Romanov family as symbols of stability, and resented their inability to quash the revolution. When Nicholas refused to back down and change his policies, radicals within the government decided that removing him would be their best chance at taking control.
On July 17th, 1918, Nicholas and his wife Alexandra were shot while on vacation in Siberia. Their five children were also killed, including three-year-old Alexei and 18-month-old Maria.