Florence Nightingale's most famous contribution came during the Crimean War, which became her central focus when reports got back to Britain about the horrific conditions for the wounded. On 21 October 1854, she and the staff of 38 women volunteer nurses that she trained, including her aunt Mai Smith, and fifteen Catholic nuns (mobilised byHenry Edward Manning)were sent (under the authorisation of Sidney Herbert) to the Ottoman Empire. They were deployed about 295 nautical miles (546 km; 339 mi) across the Black Sea from Balaklava in the Crimea, where the main British camp was based. Nightingale still believed that the death rates were due to poor nutrition, lack of supplies and overworking of the soldiers. After she returned to Britain and began collecting evidence before the Royal Commission on the Health of the Army, she came to believe that most of the soldiers at the hospital were killed by poor living conditions. This experience influenced her later career, when she advocated sanitary living conditions as of great importance. Consequently, she reduced peacetime deaths in the army and turned attention to the sanitary design of hospitals