The castle is located in the town of Egremont and above the River Ehen. The W gateway of Egremont castle appears to be the only part of the castle to have preserved Romanesque carved stonework. Most significantly this can be found in the four interior corners, where coursed corner shafts with their capitals and bases remain. It is probable that a rib vault covered the ground-floor space, but, although the vault has survived, the ribs no longer exist.

Ranulf le Meschin acquired the lordship of Appleby in Westmorland in about 1101 through his marriage to Lucy, widow and heir of Ivo Taillebois. But Ranulf seems to have been given even more lands in Cumbria by King Henry I after 1106, for his support in the Battle of Tinchebrai, although some writers say he had received these lands before then. His new position made him lord not only of Appleby, but also of Carlisle and Cumberland. On the death of Richard d’Avranches, Earl of Chester and Ranulph’s cousin, in the White Ship disaster of 1120, Ranulf became the 3rd Earl of Chester. Soon afterwards, he seems to have given the barony of Copeland to his younger brother William, called William de Meschin, who moved the caput of his fee to Egremont, thus becoming the first lord of Egremont. William appears to have died in the early 1130s. It is possible, but not certain, that he was succeeded by a son named Ranulph. If so, this was the Ranulph who founded Calder Abbey in 1134, but there is confusion over this and the reference may be to Ranulph de Gernon, 4th Earl of Chester. If Ranulph, son of William de Meschin, did succeed his father, he must have died not long after this. William fitz Duncan, nephew of the King of Scotland, married the daughter and heir of William de Meschin sometime in the 4th decade of the 12th century, and thus became lord of Egremont and Skiption. A William of Egremont appears as a primary witness in a confirmation document dated between 1157-63. This seems to be William fitz Duncan, as William of Lancaster, possibly castellan under fitz Duncan, is listed separately. Reginald de Lucy married fitz Duncan’s daughter Amabel (or Annabel) and, after fitz Duncan’s death, gained control of the lordship of Egremont in the last quarter of the 12thc. The borough of Egremont, itself, was only finally incorporated in the early 13thc, by Richard de Lucy, Reginald’s son. In the 13thc, the castle passed through marriage into the hands of the de Multon family. Then, in 1315 Robert the Bruce invaded England and the castle at Egremont was besieged. Robert the Bruce invaded again in 1322, at which time Egremont seems to have been further despoiled. This led to a period of re-building at the castle. In 1324, “Johannes de Multon habuit ingressum in castellum de Egremont…”. The castle may have fallen into a certain amount of disuse following the death of John de Multon in 1334-5, when his estate was split up. In a survey of 1578, Egremont castle was said to be in ruins.

It appears that William de Meschin was most probably responsible for the start of construction of the stone castle, presumably begun not long after he moved the caput of his fee to Egremont. Thurlby (2004) suggests a date in the 1120s for the gatehouse. Others have proposed dates of c.1120, c.1125, c.1130, and even later, for the actual start of construction of the castle. The inclusion of herringbone stonework in the lower walling of the gate and wall to the N of it have suggested to some that there may have been two early, but different, building phases. Excavations in 1993, however, showed that the herringbone work found on the exterior face of the wall north of the gateway was used as a revetment and did not occur above the original ground level of the bailey, nor was it used on the opposite side of the wall. The herringbone work found on the N and S walls of the gateway are built as bands of no more than three courses, below and to the sides of which are coursed blocks of stone. All the herringbone work of the gateway is found above the bases of the corner shafts. William de Mechines founded St Bees Priory sometime between 1120 and 1134, and gave the ‘chapel’ of Egremont to it. A date sometime in the later 1120s or in the fourth or fifth decades of that century would seem to fit best for the construction of the relevant parts of the gateway.