French Morocco had from 1912 to 1935 one of the largest 600 mm (1 ft 11 5⁄8 in) gauge network in Africa with a total length of more than 1700 kilometres. After the treaty of Algeciras where the representatives of Great Powers agreed not to build any 1,435 mm (4 ft 8 1⁄2 in) standard gauge railway in Morocco until the standard gauge Tangier - Fes Railway being completed, the French begun to build military 600 mm (1 ft 11 5⁄8 in) gauge lines in their part of Morocco French Morocco.