No strangers to murder...

1. Peter I, (the Great), who had his first born son, the heir to the throne Alexei, condemned for treason. Alexei was subsequently flogged to death.
2. The Tsarevitch Alexei.
3. Peter III, who married a minor German princess, Sophia Augusta Frederica. That princess became the Empress, Catherine the Great, upon Peter's death by poisoning in 1762.
4. Catherine the Great. She may indeed have had an indirect hand in Peter's death.
5. Tsar Paul I, ("Mad Paul") who was murdered at the request of his own first born son. Upon Paul's death, that son became Alexander I.
6. Alexander I.
7. Alexander II, who was murdered by an anarchist in March of 1881, while on his way to review the troops on a Sunday morning. Oddly enough, the assassin in this case was a brother of a young Vladimir Ilyich Lenin, and was subsequently hung by the Romanovs for his crime.
8. Sergei Alexandrovich Romanov, an uncle of Nicholas II. An anarchist threw a bomb in his lap in March of 1905. He was literally blown to bits.
9. Mikhail Alexandrovich Romanov, youngest brother of Nicholas II. Murdered by the Bolsheviks along with his secretary in Perm in June of 1918.
10. Princess Elizabeth of Hesse, wife of Sergei, was beaten and thrown down a mine shaft in July of 1918 by the Bolsheviks.

There was yet another murder within the Romanov family which had completely escaped my attention. It was of the infant Ivan VI. He was proclaimed Tsar shortly after birth and "ruled" for about one year. When he was less than two years old, he was banished via a palace revolution/dynastic crisis by Elizabeth I and imprisoned for over twenty years and subsequently murdered on the orders of same. A coin bearing his likeness is shown below.