Mikhail Alexandrovich Romanov, Grand Duke of the Russian Empire, was the younger brother of Tsar Nicholas III and the son of Alexander III. A famous political figure in early 20th century Russia, Mikhail was assassinated in 1907. His assassination triggered the start of the Fourth World War after the German refusal to turn over the assassins. Mikhail was also one of the main reasons the Franco-Russian alliance was prevented from falling apart, as he was married to Vivianne of France, the younger sister of Napoleon III and the daughter of Marcel. Mikhail left behind three children, and was the heir to the Russian throne before the birth of Alexei III. Mikhail also held a regency of the Russian throne during 1901, when it was thought that his brother Nicholas was going to die. Mikhail was not recognized as a Tsar of Russia until Mikhail Konstantinovich adopted the regnal name Mikhail III.