year. The historian Ammianus Marcellinus, circa 320–395, is the only source detailing the initial invasion of Armenia. Southern (1999, 149) dates the invasion to 295; Barnes (1982, 17, 293) mentions an earlier, unsuccessful invasion by Narseh based on the fact that the title Persici Maximi was given to all four emperors; Odahl (2004, 59) concurs with Barnes and suggests that Saracen princes in the Syrian desert collaborated with Narseh's invasion. Narseh then moved south into Roman Mesopotamia, where he inflicted a severe defeat on Galerius, then commander of the eastern forces, in the region between Carrhae (Harran, Turkey) and Callinicum (Raqqa, Syria). Diocletian may or may not have been present at the battle, but presented himself soon afterwards at Antioch, where the official version of events was made clear: Galerius was to take all the blame for the affair. In Antioch, Diocletian forced Galerius to walk a mile in advance of his imperial cart while still clad in the purple robes of an emperor. The message conveyed was clear; the loss at Carrhae was not due to the failings of the empire's soldiers, but due to the failings of their commander, and Galerius' failures would not be accepted. Galerius' position at the head of the caravan possibly was merely the conventional organization of an imperial progression, designed to show a Caesar's deference to his Augustus. Galerius's army was reinforced probably in the spring of 298 by new contingents collected from the empire's Danubian holdings. Narseh did not advance from Armenia and Mesopotamia leaving Galerius to lead the offensive in 298 with an attack on northern Mesopotamia via Armenia. Diocletian may or may not have been present to assist the campaign. Narseh retreated to Armenia to fight Galerius' force, to Narseh's disadvantage; the rugged Armenian terrain was favorable to Roman infantry, but not to Sassanid cavalry. Local aid gave Galerius the advantage of surprise over the Persian forces, and, in two successive battles, Galerius secured victories over Narseh. During the second encounter, the Battle of Satala in 298, Roman forces seized Narseh's camp, his treasury, his harem, and his wife. Narseh's wife would live out the remainder of the war in Daphne, a suburb of Antioch, serving as a constant reminder to the Persians of the Roman victory. Galerius advanced into Media and Adiabene, winning continuous victories, most prominently near Theodosiopolis (Erzurum), and securing Nisibis (Nusaybin) before 1 October 298. He