[citation needed] His governorship marked the beginnings of the restoration of the Calvert family's control of Maryland.

Very few details of his early life survive, other than the fact that he served in Spain and Portugal during the War of the Spanish Succession.

Calvert calculated that the chief impediment to the restoration of his family's title to Maryland was his Catholicism,[4] and he therefore converted to Anglicanism, deciding to "embrace the protestant religion", and gambling that this move would win back his family's lost fortune in the New World.

Benedict's father Charles Calvert, 3rd Baron Baltimore, furious at his son's apostacy, withdrew his annual allowance of £450 and ended his support for his grandchildren's education and maintenance.

[4] Hart's governorship therefore marked the beginnings of the restoration of the Calvert family's control of Maryland.