Earl of Ardglass
The title Earl of Ardglass was created in the Peerage of Ireland on 15 April 1645. The Earl held the subsidiary titles of Baron Cromwell and Viscount Lecale. All three titles became extinct in 1687.
Barons Cromwell (1540)
- Gregory Cromwell, 1st Baron Cromwell
- Henry Cromwell, 2nd Baron Cromwell
- Edward Cromwell, 3rd Baron Cromwell
- Thomas Cromwell, 4th Baron Cromwell