Just prior to the Glorious Revolution, in which William of Orange and his queen, Mary, assumed the throne of England, the colonies of Maryland and Pennsylvania became embroiled in a dispute over their mutual boundary. George Calvert, Lord Baltimore, the proprietor of the Colony of Maryland, returned to England to attempt to settled the dispute with William Penn. In his place as acting governor of the colony, Calvert had named his nephew, George Talbot. The proprietor's trip to England was not only occasioned by the boundary dispute; King James had summoned him to defend himself against charges of interfering with the royal customs collectors and of favoring Roman Catholicism. While Calvert was in England, he was called to account for the murder on 31 October 1684 of Christopher Rousby, a customs collector, by Talbot.
The outcome of the various charges against Calvert was that he was fined £2,500 for his interference with the customs collectors, the charges of pro-Catholicism were dropped, and his nephew, Talbot, was sentenced to death (the latter being commuted to five year's banishment by the king.) But more damaging to Calvert than the charges, their sentences and the embarassment of his nephew was the anti-proprietary sentiment that developed throughout his colony. That sentiment was first voiced publicly on 24 November 1688 by the Assembly when it disapproved the appointment of William Joseph by Calvert to the position of governor.
Rumors that Roman Catholicism was to be made the official state religion of the colony fueled the anti-proprietary sentiment.
The accession to the throne by Protestants, William and Mary, relieved the people of Maryland from their fears and gave them renewed motivation to remove Calvert from his position as Proprietor. On 27 July 1689, a group of about two hundred and fifty residents primarily from Charles County, calling itself the Protestant Association, and led by John Coode, captured the colony's capital of St. Mary. Then, on 22 August the Protestant Association called for a session of the Assembly, and a petition was drawn up asking for Calvert's removal. At the same session, Nehemiah Blakiston was named as the Assembly's president.
William and Mary expressed their support of the government established in Maryland by the Protestant Association on 01 February 1690. A year later, on 27 June 1691, the colony was declared to be a royal province, with George Calvert, Lord Baltimore, deprived of his proprietary rights.