Dux Britanniarum was a military post in Roman Britain, probably created by Diocletian or Constantine I during the late third or early fourth century.[citation needed] The Dux (literally, "(military) leader") was a senior officer in the late Roman army of the West in Britain. It is listed in the Notitia Dignitatum as being one of the three commands in Britain, along with the * Comes Britanniarum and * Count of the Saxon Shore.