Cecil Calvert, 2nd Baron Baltimore, was an English nobleman, also often known as Cecilius Calvert, who was the first Proprietor of the Province of Maryland, ninth Proprietary Governor of the Colony of Newfoundland and second of the colony of Province of Avalon to its southeast. His title was "First Lord Proprietary, Earl Palatine of the Provinces of Maryland and Avalon in America". He received the proprietorship after the death of his father, The 1st Baron Baltimore, for whom it had been intended. Cecil, Lord Baltimore, established and managed the Province of Maryland from his home, Kiplin Hall, in North Yorkshire, England. As an English Roman Catholic, he continued the legacy of his father by promoting religious tolerance in the colony.
Maryland became a haven for Catholics in the New World, particularly important at a time of religious persecution in England. Lord Baltimore governed Maryland for forty-two years. He also continued to be Lord Proprietor and Governor of Newfoundland for the Province of Avalon.