The siege of Paris of 885–886 was part of a Viking raid on the Seine, in the western part of the Frankish Empire. The siege was the most important event of the reign of Charles the Fat and a turning point in the fortunes of the Carolingian dynasty and the history of France. It also proved for the Franks the strategic importance of Paris at a time when it also was one of the largest cities in West Francia. The siege is the subject of an eyewitness account in the Latin poem Bella Parisiacae urbis of Abbo Cernuus.