[1] It is unclear whether he was related to Walter Fitz-Symond, described as a "gentleman of Dublin", who in 1465/6 was threatened with a lawsuit by two London merchants to whom he acknowledged that he was in debt for £40.[5] Like most of the Anglo-Irish nobility (except his brother-in-law, Lord Howth) he made the mistake of supporting the claim of the pretender Lambert Simnel to the English throne, and was present at his coronation as "King Edward VI" in Christchurch Cathedral, Dublin, although it is unclear if he officiated.After the crushing of Simnel's cause at the Battle of Stoke Field, Fitzsimon was pardoned and played a prominent part in the ceremony by which the Irish nobles expiated their treason.In 1492 he became Lord Deputy of Ireland [7] and convened a Parliament at Dublin which was largely devoted to annulling measures previously taken against him by his principal political opponent, Baron Portlester.[8] At the same time he urged that the younger sons of the nobility, whom he denounced for their incorrigible idleness, should be encouraged to learn a useful trade rather than live off their parents.