Earl of Castlemaine
The Earldom of Castlemaine was a title created in the Peerage of Ireland. It was created for Roger Palmer, the son of Sir James Palmer, a Gentleman of the Bedchamber under King Charles I, and Catherine Herbert, daughter of William Herbert, 1st Baron Powis. Roger Palmer was also the husband of Barbara Palmer, mistress to King Charles II. The Earl was also given the title Baron Limerick. The earldom was named after Castle Maine in County Kerry.
The title was limited to his male heirs by Barbara, making it clear that the earldom was for his wife's services to the King, and not his own. As the only child officially fathered by the 1st Earl was female, the title became extinct on his death.
The seat of the Palmer family is Dorney Court, Dorney, Buckinghamshire.