Piers FitzThomas Butler of Duiske (died 1601), was the illegitimate son of Thomas Butler, 10th Earl of Ormond. The lands of Duiske Abbey had reverted to his father. In 1597, the earl executed a deed of conveyance in his favour for the lands (when Piers had reached maturity).

Marriage and issue

He married Katherine Fleming, the eldest daughter and co-heiress of Thomas, Lord Slane. They had two sons. Piers was succeeded by Sir Edward Butler of Duiske

Edward Butler, 1st Viscount Galmoye

Sir Edward Butler, 1st Viscount Galmoye was the son of Piers FitzThomas Butler and the Honourable Katherine Fleming. His father was the illegitimate son of Thomas Butler, 10th Earl of Ormond....

, knt. On 16th May 1646, Edward was created Viscount Galmoye.