Benedict Leonard Calvert, 4th Baron Baltimore was an English peer and politician. He was the second son of Charles Calvert, 3rd Baron Baltimore (1637–1715) by Jane Lowe, and became his father's heir upon the death of his elder brother Cecil in 1681. The 3rd Lord Baltimore was a devout Roman Catholic, and had lost his title to the Province of Maryland shortly after the events of the Glorious Revolution in 1688, when the Protestant monarchs William III and Mary II acceded to the British throne. Benedict Calvert made strenuous attempts to have his family's title to Maryland restored by renouncing Roman Catholicism and joining the Church of England.

Charles Calvert, 3rd Baron Baltimore was an English peer and colonial administrator. He inherited the province of Maryland in 1675 upon the death of his father, Cecil Calvert, 2nd Baron Baltimore. He had been his father's Deputy Governor since 1661 when he arrived in the colony at the age of 24. However, Charles left Maryland for England in 1684 and would never return. The events following the Glorious Revolution in England in 1688 would cost Calvert his title to Maryland; in 1689 the royal charter to the colony was withdrawn, leading to direct rule by the British Crown. Calvert's political problems were largely caused by his Roman Catholic faith which was at odds with the established Church of England.