Nicholas II of Russia
On 1 March 1881, following the assassination of his grandfather, Tsar Alexander II, Nicholas became heir apparent upon his father's ascension as Alexander III. Nicholas and his other family members bore witness to Alexander II's death, having been present at the Winter Palace in Saint Petersburg, where he was brought after the attack. For security reasons, the new tsar and his family relocated their primary residence to the Gatchina Palace outside the city, only entering the capital for various ceremonial functions. On such occasions, Alexander III and his family occupied the nearby Anichkov Palace.
Nicholas II of Russia
Further complicating domestic matters was the matter of the succession. Alexandra bore Nicholas four daughters, the Grand Duchess Olga in 1895, the Grand Duchess Tatiana in 1897, Grand Duchess Maria in 1899, and Grand Duchess Anastasia in 1901, before their son Alexei was born on 12 August 1904. The young heir was afflicted with Haemophilia B, a hereditary disease that prevents blood from clotting properly, which at that time was untreatable and usually led to an untimely death. As a granddaughter of Queen Victoria, Alexandra carried the same gene mutation that afflicted several of the major European royal houses, such as Prussia and Spain. Hemophilia therefore became known as "the royal disease". Through Alexandra the disease had passed on to her son. As all of Nicholas and Alexandra's daughters perished with their parents and brother in Yekaterinburg in 1918, it is not known whether any of them inherited the gene as carriers.