Henry Percy, an associate of John of Gaunt, was originally a follower of Edward III of England, for whom he had held high offices in the administration of northern England.

At a young age he had been made Warden of the Marches towards Scotland in 1362, with the authority to negotiate with the Scottish government.

He had been entrusted in February 1367 with the supervision of all castles and fortified places in the Scottish marches.

He goes on to support King Richard II and is in 1377 created an Earl and briefly given the title of Marshal of England.