William de Londres

Construction of Ogmore Castle might have started around 1106,[1] its foundation predating the Norman conquest.[3] In Caradoc of Llancarfan's The historie of Cambria, now called Wales: a part of the most famous yland of Brytaine, Caradoc wrote that the manor and castle were given to William de Londres, one of the legendary Twelve Knights of Glamorgan, by Robert Fitzhamon, the Norman conqueror of Glamorgan.[5] In 1116, William de Londres was forced to abandon the castle when the Welsh appeared in force.[6] His butler, Arnold, is credited with protecting the castle from the Welsh attack during the absence of William de Londres, and for this, he was knighted Sir Arnold Butler, also receiving the castle and manor of Dunraven as reward.[7]

According to the custom of the times, the founding of a religious institution followed the acquisition of power. William de Londres, or his descendant John, built Ewenny Abbey 1 mile (1.6 km) from the castle. Also nearby was a religious place appended to Ogmore Castle by Morris de Londres or his descendant John, in 1141; Ewenny Priory is 2 miles (3.2 km) from Ogmore Castle. When Thomas' heiress married into the Chaworth family of Kidwelly,[6] the lands passed in 1298 to the first Duke of Lancaster.[4]

from http://en.wikipedia.org/wiki/Ogmore_Castle

Please see Darrell Wolcott: The Royal Family of Glamorgan: The Conquest of Glamorgan-Futher Notes; http://www.ancientwalesstudies.org/id226.html. (Steven Ferry, December 31, 2018.)