The Battle of Teruel was fought in and around the city of Teruel during the Spanish Civil War between December 1937 and February 1938, during the worst Spanish winter in 20 years. The battle was one of the bloodiest actions of the war, with the city changing hands several times by first falling to the Republicans and eventually being retaken by the Nationalists. In the course of the fighting, Teruel was subjected to heavy artillery and aerial bombardment. In the two-month battle, both factions together took 110,000 casualties. With his superiority in men and material, Nationalist leader Francisco Franco regained Teruel. This battle became the military turning point of the war. The Republic's decision to move against Teruel was motivated by several strategic priorities. Republican military leaders thought that Teruel was not strongly held and sought to regain the initiative by its capture. By 1937, the Teruel salient was similar to the fingernail on a finger of Nationalist territory inserted into Republican Spain, and its capture would shorten the lines of communication between central Republican Spain and Valencia on the coast. Teruel was surrounded on three sides by Republican Spain. In addition, Teruel was a symbol of Nationalist power on the Aragon front. Indalecio Prieto, the Republic's Minister of War, wanted a spectacular victory to reflect well on his tenure and to show how the army could function under his reorganization. A victory at Teruel would also aid the government of Prime Minister Juan Negrín in its quest to take over the industries of Catalonia from their workers. Lastly, Republican intelligence learned that Franco intended to start a major offensive against Madrid in the Guadalajara sector on 18 December and so the Republicans wanted to divert the Nationalists away from the Madrid area. The Republic, therefore, started the battle on 15 December. Teruel, in southern Aragon, had a population of 20,000 and was the remote capital of a poor province. It had been fortified in 1170 to buffer the warring Moorish and Christian states.