n 39 BC, the tribe of the Ubii entered into an agreement with the Roman forces and settled on the left bank of the Rhine. Their headquarters was Oppidum Ubiorum — the settlement of the Ubii, and at the same time an important Roman military base. In 50 AD, Agrippina the Younger, wife of the Emperor Claudius, who was born in Cologne, asked for her home village to be elevated to the status of a colonia — a city under Roman law. It was called Colonia Claudia Ara Agrippinensis (a "colony of Claudius and the altar of Agrippina"), or Colonia Agrippina, "the Colony of Agrippina". In 80 AD water supply was built, the Eifel Aqueduct, one of the longest aqueducts of the Roman Empire, which delivered 20,000 cubic metres of water to the city every day. Ten years later, the colonia became the capital of the Roman province of Lower Germany Germania Inferior with a total population of 45,000 people.