Robert Curthose (c. 1054–1134) was the eldest son of William the Conqueror and a central figure in the turbulent politics of Anglo-Norman England in the generation after the Conquest. Although designated heir to the Duchy of Normandy, Robert’s career was marked by chronic financial weakness, political miscalculation, and ultimately long captivity.

In 1096, Robert mortgaged Normandy to his brother William II of England in order to raise funds to participate in the First Crusade. While Robert was absent in the eastern Mediterranean, William II ruled both England and Normandy. William’s sudden death in 1100 created a succession crisis that Robert was slow to exploit.

On his return from the crusade, Robert was preparing to strengthen his position through marriage when his youngest brother Henry I of England seized the English throne. Robert invaded England in 1101 to press his claim, but the ensuing struggle between the brothers dragged on inconclusively for several years.

The conflict was decisively settled in 1106, when Henry defeated Robert at the Battle of Tinchebray in Normandy. Robert was captured and spent the remainder of his life in captivity, initially at Devizes Castle and later at Cardiff Castle.

Robert died in 1134 after nearly three decades of imprisonment. He was buried in the abbey church of St Peter at Gloucester, later incorporated into Gloucester Cathedral, where his tomb became part of the cathedral’s architectural and commemorative history.