Alexei Nikolaevich was the Tsarevich of Russia from 1894 to 1918. He was the eldest son of Tsar Nicholas II and Tsarina Alexandra, and the last heir to the Russian throne. He suffered from hemophilia, a genetic disorder that prevented his blood from
From Wikipedia
Alexei Nikolaevich Romanov was the last Russian tsesarevich. He was the youngest child and only son of Tsar Nicholas II and Tsarina Alexandra Feodorovna. He was born with haemophilia, which his parents tried treating with the methods of peasant faith healer Grigori Rasputin.