St Quintins Castle site was first occupied with a defensive structure in about 1102 and the gatehouse and further building work took place around 1312. It was later used as a prison and was reported as being in a ruinous state by 1741.
Around 1102 Robert Fitzhamon, the first Norman Lord of Glamorgan bequeathed the lands of Llanblethian as a lordship to Herbert de St Quentin who is thought to have built the first fortification at the site of the castle. This initial construct was believed to have been a simple ringwork defence with timber walls, a bank and ditch. A rectangular stone keep was built in the late 12th century, whose remains can now be found within the later gatehouse. This keep may have replaced a similar wooden structure.
The lordship remained with the St Quentin family until 1233 when the land was seized by Richard Siward, but he then lost it to Earl Richard de Clare in 1245. Richard de Clare seized large areas of this part of Glamorganshire, from Cowbridge to Llantrisant, but it was his grandson, Earl Gilbert de Clare, who began to build the stone structure of St Quintins Castle which stands today. This was thought to have been roughly after 1307, but Gilbert de Clare was killed in the Battle of Bannockburn in 1314 before the castle was completed. Modern historians believe that the lack of inner courtyard buildings and the weakness of the curtain wall points to the hypothesis that the castle was never fully completed.
The castle itself is a rectangular stone walled enclosure, roughly 64 metres East to West. The walls are roughly 120 centimetres in thickness. It is set on a spur above steep slopes on all sides apart from the East side. The weak East side of the fortification is protected by a twin-tower gatehouse and a further two towers East entrance facade. The best defensive side is the southern side which falls away sharply to the River Thaw. It was reported as being ruinous by 1741.
The base of a semi-octagonal tower can be seen at the southeast corner of the castle and parts of a tower at the southwest corner. The ivy-clad gatehouse is between these and is a substantial structure where you can see the slits for the two portcullises and the fittings for the sets of strong doors. The remains of the keep are largely rubble and little remains of the bailey walls on the east, north and south sides.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.