Carew's claim became complicated when it appeared to encroach upon the possession and authority of the Butler family, an Anglo-Norman dynasty with wide influence in Ireland, whose principal was Sir Thomas Butler, 10th Earl of Ormond. Butler's younger brother, Edmund, held the castle of Clogrenan a few miles north of Leighlin – it had been purchased from the Kavanaghs by his father – and in protest at this encroachment, which he expected would extend to his own lands, he launched an attack on Carew, who retaliated by storming Clogrenan and seizing it with little difficulty. The land seizure caused great disquiet locally and eventually led to the Butler Wars, which contributed to a wider insurrection, the first of the Desmond Rebellions.