 Possibly commissioned by William fitz Osbern, the Earl of Hereford, it was originally an earthwork design with timber defences.In 1135, a major Welsh revolt took place, and in response King Stephen brought together Grosmont Castle and its sister fortifications of Skenfrith and White Castle to form a lordship known as the "Three Castles", which continued to play a role in defending the region from Welsh attack for several centuries.King John gave the castle to a powerful royal official, Hubert de Burgh, in 1201.