Siege of Chartres
911 CE.
Shown on the map at 48.447°, 1.488°.
The siege of Chartres took place in spring 911 during the age of Viking incursions in Europe. The Viking leader, Rollo, and his men laid siege to the city of Chartres, in West Francia. They failed to achieve their goal before the arrival of a relief army in July 911, at which point an engagement ensued which resulted in the defeat of the Norsemen. Despite the frequent occurrence of Viking raids against the Frankish realms, their failure to succeed in this siege would prove to have everlasting consequences on European history. Following Rollo's defeat, the King of the West Franks, Charles the Simple, granted him a territory in the northern lands of his kingdom in exchange of an oath of fealty and his religious conversion. This territory, located between the mouth of the Seine and Rouen, a city Rollo had previously raided and seized in 876, officially formed the fief known as the County of Rouen. This county, through kinship in the decades to come, would expand into what came to be known as the Duchy of Normandy.
Text from the Wikipedia article Siege of Chartres (911), licensed CC BY-SA 4.0.