2000 year ago, approximately, during the 1st century, the Gauls founded and named it Ratumacos. The Romans came a century or two later and called it Rotomagus. In the 5th century, it became Rouen, under the Roman Catholic Archdiocese. The Normans conquered it in the 9th century, after which point it became the capital of the Duchy of Normandy where one of its most famous sons, William the Conqueror, rose to power (though he then moved his political base to Caen). From that point on and until today, Rouen has birthed more impressive sons and daughters, crowned dukes and kings, and has remained the crown jewel of Normandy.