The PC class were named after Iraq's four principal cities: Baghdad, Mosul, Basra and Kirkuk. 502 "El Mosul" was the first to be delivered, in March 1941. Thereafter the April 1941 Iraqi coup d'état installed a government allied to Fascist Italy and Nazi Germany and delivery of the remaining members of the class was delayed until after the British invasion of Iraq in May 1941 and invasion of Vichy-ruled Syria and Lebanon in June and July. 501 "Bagdad" was delivered in October 1941 and 503 "El Basra" in December. 504 "Kirkuk" was lost "en route" and did not enter service. Early in 1948 Iraqi State Railways renumbered its locomotive fleet and 501–503 became 1501–1503.