In 1941, the General Anaya borough was merged with the Central Department, which was then renamed "Mexico City" (thus reviving the name but not the autonomous municipality). From 1941 to 1970, the Federal District comprised twelve ''delegaciones'' and Mexico City. In 1970, Mexico City was split into four different ''delegaciones'': Cuauhtémoc, Miguel Hidalgo, Venustiano Carranza and Benito Juárez, increasing the number of ''delegaciones'' to 16. Since then, the whole Federal District, whose ''delegaciones'' had by then almost formed a single urban area, began to be considered ''de facto'' a synonym of Mexico City.