Simplify the following text for a Grade 9 native English-speaking person.
Original: In February 1917 , Nicholas II abdicated the throne and Anastasia and her family were placed under house arrest at the Alexander Palace in Tsarskoye Selo during the Russian Revolution .
Simplified: In February 1917 , Nicholas II resigned from the throne . Anastasia and her family were placed under house arrest at the Alexander Palace in Tsarskoye Selo during the Russian Revolution .