The Percy family had supported Bolinbroke [later Henry lV] when he deposed Richard ll in 1399. But they felt their rewards had not been sufficient. Scots invasions/incursions were repulsed mainly be the Percy's protecting the border. For this service they also felt unrewarded or even recompensed. The last straw was when Mortimer [Percy's brother-in-law] was ransomed by Glyndwr and the King did not contribute. The Percy's allied themselves with Glyndwr and rose in rebellion. They were defeated at the Battle of Shrewsbury.

• Shrewsbury 21 July 1403