Complex sentence: Some of Hicks's later work may be seen at Belle Isle, Fermanagh, where he was commissioned by the Duke of Abercorn to redecorate the interior of the castle in the 1990s, having decorated the duke's main house, Baronscourt, in the 1970s.
Split into simpler sentences: Some of Hicks's later work may be seen at Belle Isle, Fermanagh, the Duke of Abercorn hired him to redecorate the interior of the castle in the 1990s. Hicks decorated the duke's main house, Baronscourt, in the 1970s.