The title Earl of Kerry was created in 1723 for Thomas Fitzmaurice, the holder of the ancient Irish barony of Kerry, which was created in the thirteenth century. The fourth Earl had previously succeeded to the Marquessate of Lansdowne, and the titles have remained merged since.
Baron Kerry is an ancient title in the Peerage of Ireland.
His younger son John Petty was created Earl of Shelburne in the Peerage of Ireland in 1753 and his son, the second Earl of Shelburne, was created Marquess of Lansdowne in 1784.
In 1818 the latter's son, the third Marquess, succeeded his cousin as 4th Earl of Kerry and 24th Baron Kerry.