Hungary - Ruins of Aquincum

Aquincum was originally settled by the Eravisci, a Celtic tribe. Aquincum served as a military base (castrum), having been part of the Roman border protection system called limes. Around AD 41–54, a 500-strong cavalry unit arrived, and a Roman legion of 6,000 men (Legio II Adiutrix) was stationed here by AD 89. The city gradually grew around the fortress, and after Pannonia was reorganised by the Romans in AD 106, Aquincum became the capital city of the Roman province of Pannonia Inferior, holding that position until the administrative reform of Diocletian, more than a hundred years later. Under Hadrian, the city obtained municipal status, while under Septimius Severus, Aquincum became a colonia