The Burnell family had been Lords of the Manor of Balgriffin, County Dublin since the fourteenth century: they acquired the manor of Castleknock through marriage into the Tyrrell family, who had held the feudal barony of Castleknock, and died out around 1370.
[2] The family tradition of judicial service was continued by Henry Burnell (died 1614), who was Recorder of Dublin and a judge of the Court of King's Bench (Ireland).
Elrington Ball explains that a Deputy was required because Oliver was considered to be mentally deficient.
In 1491 he and Oliver were appointed joint Chief Barons,[2] presumably due to Portlester's influence, but Burnell seems to have died soon afterwards.
[3] His burial place was within the private chapel of Baron Portlester at St. Audoen's Church, where his tombstone survives.