According to Vera Leonidovna, "Handsome Felix had what are called "grammatical errors"; that is, he was bisexual, plain and simple....Gossip outlives people. But the two of them---they were an
amazing couple---they were so attractive. What bearing! Breeding!" On 9 February 1914 in St.Petersburg, Prince Felix Felixovitch Youssoupov married Princess Irina Alexandrovna of Russia, a niece of Emperor Nicholas II. On 8 March 1915 their daughter, Xenia, was born. Prince Felix was present in the Duma to hear the speech of Purishkevich denouncing the 'dark forces' which were destroying the monarchy. However, the 'dark forces' was a reference to Rasputin and
the day after the speech Prince Felix called on Purishkevich. Knowing by experience that the Emperor would not listen to criticism of Rasputin, he decided to kill the 'starets' but needed assistance. Purishkevich agreed to help and three others were found: the 26-year-old Grand Duke Dimitri; Sukhotin, an army officer; and Lazovert, a doctor.

Youssoupov was to invite Rasputin to his house and poison him, the others disposing of the body. Everything went to plan except that Rasputin would not die. Though he had drunk two glasses of poisoned wine and devoured two poisoned cakes, he merely began to sing. Then Prince Felix Youssoupov shot him in the back and, apparently dead, Rasputin fell. Having turned away from Rasputin, he suddenly heard a roar and Rasputin was on his feet again and lurching towards him.
Fearing the supernatural powers of Rasputin, he was convinced he was facing a devil. Terrified, he ran to his friends while Rasputin reached the front door and walked into the courtyard. Purishkevich ran after him and fired four times at Rasputin's back, hitting him twice. Once again, Rasputin fell to the ground. This time they bound him hand and foot and took him to the river Neva, where they made a hole in the ice and dumped him in. When the corpse was found three days later, it was established that he had died from drowning.

They had hoped the conspiracy would have remained secret, but quickly the whole town knew not only that Rasputin was dead but also who had killed him. A few days later Grand Duke Dimitri went to the theatre but had to leave in embarrassment because of the standing ovation he received. However, Grand Duke Dimitri was sent to the Russian troops in Persia and this exile saved Dimitri's life at the beginning of the Russian Revolution. Meanwhile Prince Felix was banished to one of his estates.

After the revolution Prince Felix and his wife and daughter were able to move to London, with funds from the sale of some Rembrandts and jewels. Here he generally acted as the centre of the Russian colony in exile.
 

Source: Leo van de Pas