Guildford Castle is an 11th century earthwork motte & bailey fortress, originally it was founded by the famous William the Conqueror. In the early twelth century, King Henry I founded this stone castle upon adding a polygonal shell keep to the motte. In the 1130s, a 2 storey square keep, was built on the slope of the motte, flanking the shell keep both sides & a further outer bailey was added, encased by a large ditch. During the 13th century, King Henry III ordered many more improvements to the domestic buildings & the outer bailey was extended, flanked by a new gatehouse. In the 14th century, the royal residence in the outer bailey, known has The Palace & was detached from the castle, by a palisade & ditch.