Colonia Ulpia Traiana (CUT) was a Roman town near the German city of Xanten.
The city was named after Emperor Trajanus, who had given her the status of Colonia around the year 100. It belonged in the top 150 cities in the Roman Empire who possessed highest city law. With an area of 73 hectares Colonia Claudia Ara Ulpia Traiana was, after Agrippinensium (Cologne) and Augusta Treverorum (Trier), the third largest Roman city north of the Alps and one of the major cities of the province of Germania Inferior. The city was the center of a large area and public buildings show both the high status of the city as its focus on the Roman culture. In the area of the city is now the Archaeological Park Xanten established.
The history of Colonia Ulpia Traiana starts in 13/12 BC. when the Roman general Nero Claudius Drusus had build the camp Castra Vetera on the Fürstenberg (southeast of present Xanten) opposite the former mouth of the river Lippe in the Rhine. This fort served as a base for a campaign on the right bank of the Rhine in 8 BC. which led to the subjugation of the Germanic tribe of the Sugambren.
They were forced to move to the left bank of the Rhine and were hereafter referred to as Ciberni, Cuberni or Cugerni. They settled in an area northwest of Castra Vetera that already in the fourth and third centuries BC. had been inhabited by people, but in the next two centuries it was abandoned.