Whatever happened at this site before AD 100 is of little consequence: the story of Timgad begins in grand style when the Emperor Trajan decided to build a colony for soldiers and veterans of his Legion III Augusta. The Colonia Marciana Traiana Thamugadi, to give it its full name, is, in the words of the Unesco report that recommended inscribing it on the World Heritage list, ‘a consummate example of a Roman military colony’.
Timgad was intended to provide accommodation for 15, 000 in all, but it soon outgrew that number and moved beyond the original grid, with new quarters being added to the original ground plan over the next 300 years, leading to a quadrupling of the original camp. During its 2nd- and 3rd-century heyday, Timgad stood as a clear expression of Roman power in Africa – solid, brilliantly conceived and executed, and perfectly located at the head of the Oued el-Abiod and a crucial junction that gave Romans control of one of the main passes through the Aurès Mountains, and therefore of access to and from the Sahara.
There was a Christian presence at Timgad from the mid-3rd century, which grew to such prominence that a Church Council was held here in AD 397. The Vandal invasion of 430 brought an end to any centralised power and at the end of the 5th century the region was so weak that Timgad was sacked by tribes from the nearby Aurès Mountains, the very people the camp had been designed to control.
Timgad was revived in 539 under the Byzantine Emperor Justinian, when a fortress was built outside the original town, reusing many blocks from earlier Roman buildings, but this remote outpost could only survive with a strong central power and, with the Arab invasion in the 7th century, the end was at hand. The site was abandoned some time in the 8th century.