The Crimean War took place from 1853 to 1856, primarily involving Russia against an alliance of Britain, France, the Ottoman Empire, and Sardinia. The conflict arose over territorial disputes and the decline of the Ottoman Empire, particularly regarding control of the Black Sea region. The war is notable for its significant battles, such as the Battle of Balaclava and the Siege of Sevastopol. It also marked the first use of modern military technology, including the telegraph and railways, and highlighted the need for medical reforms, leading to the work of Florence Nightingale in nursing.