Gilbert, Duke of Lorraine
Gilbert or Giselbert (c.890 – 2 October 939) was the duke of Lotharingia until 939. Lotharingia (or Lorraine) was an area which comprised present north east France, the German Rhineland, Luxembourg, east Belgium, and the Netherlands. It was not yet divided into Upper and Lower Lorraine.
The beginning of the reign of Gilbert is not clear. Lotharingia belonged to West Francia (or France) from 910, when a dux Lotharingiae is first mentioned. This may have been Gilbert. The French king Charles III was deposed in 922 by Robert. Charles remained king in Lotharingia and tried to reconquer West Francia from there. He was imprisoned in 923.
In 925, Gilbert swore fealty to King Henry the Fowler of Germany as duke of Lotharingia. Gilbert married Henry's daughter Gerberge by 930. For whatever reason, Gilbert rebelled when Henry died in 936 and changed allegiance to the king of France, where the king had less authority. Gilbert managed to be practically independent for three years until he was defeated by the army of king Otto I of Germany in 939 at the Battle of Andernach. Gilbert is made prisoner, and succeeds in fleeing but it drowned while wanting to cross the Rhine. Lorraine was given to Henry I, Duke of Bavaria.