"In Hoc Signo Vinces"

Constantine had the cross on his banner at the battle of the Milvian Bridge. According to The Times this morning archaeologists have discovered the standards of his rival, Maxentius. Or at any rate, the standard holders.

Archeologists have unearthed what they say are the only existing insignia belonging to Roman Emperor Maxentius — precious objects buried to protect them after Maxentius was defeated by his rival Constantine at the battle of Milvian Bridge in AD 321. Some of the objects are believed to be the bases for the emperor's standards — rectangular or triangular flags, Italian officials said Wednesday.

A little googling reveals a bit more than The Times's one short paragraph. The Seattle Post-Intelligencer has more detail here.