In 1201 he took control of White Castle along with the nearby castles of Skenfrith and Grosmont (which together form his ‘Three Castles’).
Yn 1201, cipiodd reolaeth ar y Castell Gwyn ynghyd â Chastell Ynysgynwraidd a Chastell Grysmwnt gerllaw (sef ei 'Dri Chastell').