 Later, in 1426, John FitzGerald, 6th Earl of Kildare reputedly "strengthened Kilkea with so many new works, that he might be said almost to have new built it.The castle is particularly associated with Gerald, the 11th Earl of Kildare known as the "Wizard Earl", who became the eldest male representative of the Geraldines when only 12 years of age after his half brother "Silken Thomas" the 10th Earl and five uncles were executed at Tyburn in 1537.The "Wizard Earl" escaped Ireland being sent to the continent to be educated, and following his return to Kildare and restoration to his titles his interest in alchemy caused much interest among his neighbours around Kilkea Castle and he was said to possess magic powers.