Lord Kildare had a keen interest in alchemy, which caused much speculation among those living around Kilkea Castle. He was rumoured to possess magic powers, and thus earned the nickname "the Wizard Earl". He was a highly intelligent and cultivated man, "a product of the Renaissance", but he seems to have lacked the political skills of his grandfather, The 8th Earl of Kildare, who virtually ruled Ireland for 35 years, and in the turbulent political atmosphere of the 1560s and 70s he was increasingly vulnerable to attack, especially since he openly professed the Roman Catholic faith. He was also unfortunate in being the father-in-law of Lord Delvin, who was suspected of treason throughout his career.