The first documented mention of the castle was in 1101-02, the structure at that time presumably a simple affair of bank, ditch and enclosure. The earliest remaining structure is the stone tower, built around half a century later by Godric Mappestone (hence the name of the castle). The classic Norman keep was built in imported stone, the grey ashlar still a contrast to the surrounding red of the later buildings. Although built for strength, this is a structure of some refinement, with pilaster buttresses emphasizing the height, and a decorative horizontal stringcourse, carved into chevrons around the second storey. Two Norman windows, with rounded tops and carved pillars further embellish the north and west sides. The entrance, as usual with Norman keeps, was on the first floor, above the present entrance. It is now blocked, but would have been reached by a wooden staircase or ladder. Inside, you can see the corbel stones, which supported the wooden floors at the different levels. To spread the load evenly on the four walls, the joists would have run in different directions.

In 1204, King John gave the castle to William Marshal on his marriage to the heiress of the earldom of Pembroke. As at his other castle at Chepstow, William set about strengthening Goodrich with stone towers and walls around the keep. Further building was carried out towards the end of the century, evidenced by the style of the barbican, gatehouse and the spurs of the drum towers.

About 1300, the keep was downgraded to create a prison and strong room, and a kitchen. The living quarters were now situated in the three ranges round the courtyard, each styled according to the rank of the inhabitants. The west was the most prestigious, with a gallery and vestibule, a private chapel for family use, and the great hall for impressing your visitors. Over on the east side, the castle staff and garrison lived, and a large latrine block is visible. There are also the remains of the larger chapel, for the whole community. In between these ranges is the north range, used by principal guests, who could be numerous. Also on this side are the remains of the solar, the lord’s private room. What is left is very impressive, as without the dividing floors, a column of stone rises high into the air, supporting two pointed arches.

The castle passed through different families, becoming disused before the Civil War. During the war, it was occupied by a Parliamentarian garrison in 1643, who left and were replaced in 1645 by Royalists. The castle was attacked by the Roundheads in 1646, the stables being burnt down and small scale hand-to-hand fighting escalating into mining of the river side of the castle by June. The 104-man garrison surrendered, despite still having supplies, but the King had given up and explosions from the mine were immanent. As elsewhere, the castle was partly demolished to prevent it being used defensively again, and it gradually fell into disrepair. At the end of the 19^th century, it was a place where visitors, William Wordsworth among them, came to admire the romance of a lost age, which, although now tidy and cleared of weeds, is partly how it functions today.