Colonia Claudia Ara Agrippinensium

Colonia Claudia Ara Agrippinensium was the Roman colony in the Rhineland from which the city of Cologne, now in Germany, developed.

It was usually called Colonia (colony) and was the capital of the Roman province of Germania Inferior and the headquarters of the military in the region. With administrative reforms under Diocletian it became the capital of Germania Secunda. Many artefacts from the ancient city survive, including the arch of the former city gate with the inscription 'CCAA', which is today housed in the Romano-Germanic Museum.