Duke of Leinster is a title in the
Peerage of Ireland and the premier dukedom in that peerage. The subsidiary titles of the Duke of Leinster are:
Marquess of Kildare (1761),
Earl of Kildare (1316),
Earl of Offaly (1761),
Viscount Leinster, of Taplow in the County of Buckingham (1747),
Baron Offaly (1620) and
Baron Kildare, of Kildare in the County of Kildare (1870). The viscounty of Leinster is in the
Peerage of Great Britain, the barony of Kildare in the
Peerage of the United Kingdom, and all other titles in the
Peerage of Ireland. The
courtesy title of the eldest son and heir of the Duke of Leinster is
Marquess of Kildare.