Public unrest over the Russo-Japanese War of 1904–1905 and demands for political reform increased in the early years of the twentieth century. At Epiphany 1905, a band of revolutionaries fired live rounds at the Winter Palace from the Peter and Paul Fortress. Olga and the Dowager Empress were showered with glass splinters from a smashed window, but remained unharmed. Three weeks later, on "Bloody Sunday" (), Cossack troops killed at least 92 people during a demonstration, and a month later Olga's uncle, Grand Duke Sergei Alexandrovich of Russia, was assassinated. Uprisings occurred throughout the country, and parts of the navy mutinied. Olga supported the appointment of the liberal Pyotr Stolypin as prime minister, and he embarked on a programme of gradual reform, but in 1911 he was assassinated. The public unrest, Michael's elopement, and Olga's sham marriage placed her under strain, and in 1912, while visiting England with her mother, she suffered a nervous breakdown. Tsarina Alexandra was also unwell with fatigue, concerned by the poor health of her hemophiliac son, Alexei. Olga stood in for the Tsarina at public events, and accompanied her brother on a tour of the interior, while the Tsarina remained at home.