The Catalonia Offensive was part of the Spanish Civil War. The Nationalist Army started the offensive on 23 December 1938 and rapidly conquered Republican-held Catalonia with Barcelona. Barcelona was captured on 26 January 1939. The Republican and Catalan governments headed for the French border. Thousands of people fleeing the Nationalists also crossed the frontier in the following month, to be placed in internment camps. Franco closed the border with France by 10 February 1939.