The first urban settlement on the grounds of what today is the centre of Cologne was Oppidum Ubiorum, which was founded in 38 BC by the Ubii, a Cisrhenian Germanic tribe. In 50 AD, the Romans founded Colonia on the Rhine and the city became the provincial capital of Germania Inferior in 85 AD. The city was named "Colonia Claudia Ara Agrippinensium" in 50 AD. Considerable Roman remains can be found in present-day Cologne, especially near the wharf area, where a notable discovery of a 1900 year old Roman boat was made in late 2007. From 260 to 271 Cologne was the capital of the Gallic Empire under Postumus, Marius and Victorinus. In 310 under Constantine a bridge was built over the Rhine at Cologne. The imperial governors of Rome resided in the city and it became one of the most important trade and production centres in the Roman Empire north of the Alps.
Maternus, who was elected as bishop in 313, was the first known bishop of Cologne. The city was the capital of a Roman province until occupied by the Franks in 462. In 785, Cologne became the seat of an archbishopric.
During the time of the Holy Roman Empire in the Middle Ages, the Archbishop of Cologne was one of the seven prince-electors and one of the three ecclesiastical electors. The archbishops had ruled large temporal domains but in 1288 Sigfried II von Westerburg was defeated in the Battle of Worringen and forced into exile in Bonn.
Cologne's location on the river Rhine placed it at the intersection of the major trade routes between east and west and was the basis of Cologne's growth. Cologne was a member of the Hanseatic League and became a Free Imperial City in 1475. Interestingly the archbishop nevertheless preserved the right of capital punishment. Thus the municipal council (though in strict political opposition towards the archbishop) depended upon him in all matters concerning criminal justice. This included torture, which sentence was only allowed to be handed down by
