Of a Burgundian family, he made his career in the court of Edward II through the patronage of Hugh Despenser the younger.
He also spent some time around 1332 as keeper of the wardrobe of the king's brother, the earl of Cornwall.
Before his appointment as treasurer in 1341, he served briefly in 1349–1350 as keeper of the king's household wardrobe.
A later appointment as archdeacon of Cornwall was challenged by a papal nominee, and Cusance was drawn into a lengthy legal battle.
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