Prince Felix Yusupov believed it was his patriotic duty to kill Grigori Rasputin, the malevolent ‘holy man’, and deliver Russia from her most dangerous internal enemy. Two Montenegrin princesses, Militsa and Anastasia, who married into the imperial family, introduced Grigori Rasputin to the Tsarina in 1905, as they believed he could heal the Tsarevich Alexei. Alexei…