Baron Baltimore

Baron Baltimore, of Baltimore Manor in County Longford, was a title in the Peerage of Ireland. It was created in 1624 for George Calvert and became extinct on the death of the sixth Baron in 1771. The title was held by several members of the Calvert family who were proprietors of the palatinates Province of Avalon in Newfoundland and Province of Maryland, later the U.S. state of Maryland. In the context of United States history, the name Lord Baltimore usually refers to Cæcilius Calvert, 2nd Baron Baltimore after whom the city of Baltimore, Maryland is named. His younger brother Leonard Calvert was the first Governor of Maryland.

As members of the Irish peerage, the Lords Baltimore were able to sit in the House of Commons. Irish peerages were often used as a way of creating peerages which did not grant a seat in the English House of Lords and so allowed the grantee to sit in the House of Commons in London. As a consequence, many Irish peers had little or no connection to Ireland.