Charles Calvert, 5th Baron Baltimore

Map of the Province of Maryland showing the area in dispute with Pennsylvania

In 1688, eleven years before Charles Calvert (1699–1751) was born, the Calvert family had lost their title to the Province of Maryland, following the events of the Glorious Revolution in England. In 1689 the Royal Charter to the colony was withdrawn, leading to direct rule by the British Crown. In 1715, when Charles was fifteen, his grandfather Charles Calvert, 3rd Baron Baltimore died, passing his title, and his claim to Maryland, to his son Benedict Leonard Calvert, 4th Baron Baltimore, (1679–1715). Benedict Calvert immediately petitioned George I for the restoration of the family's proprietarial title to Maryland but, before the king could rule on the petition, Benedict Calvert himself died, just two months after his father, passing on his title in turn to his son Charles. Charles Calvert soon found himself, aged just fifteen, in the fortunate position of having had his family's proprietarial title to Maryland restored by the king.

In 1721 Charles came of age and, at 21, assumed control of the colony of Maryland, though he appointed his cousin Charles Calvert, then a captain in the Grenadier Guards, as governor.[2]

In 1722, Charles Calvert, fifth Baron Baltimore found himself in financial difficulties and sold the Kiplin estate, his family's home since 1620, to his mother's second husband (his stepfather) Christopher Crowe for £7,000 (approximately £550,000 in modern currency) (later purchased as historical inheritance for the State of Maryland by the University of Maryland).[3]

In 1727 Lord Baltimore appointed his brother, Benedict Leonard Calvert, governor of the colony, replacing his cousin Captain Calvert. The handover of power from cousin to cousin was not entirely smooth. Captain Calvert insisted on retaining fifty percent of the 3 pence tobacco duty which was his due under legislation passed in 1727. Benedict was unimpressed, and his younger brother Cecil wrote to him that family opinion in England was appalled at Captain Calvert's behaviour, and "thinks him mad".[4] Lord Baltimore himself wrote that Benedict should receive the full benefit of the tax.[4]

Unfortunately, Benedict's health was poor and he died of tuberculosis on 1 June 1732, while sailing back to England. He was succeeded in 1732 by Governor Samuel Ogle under whose rule Maryland became engaged in a border dispute with Pennsylvania.[5] Several settlers were taken prisoners on both sides and Penn sent a committee to Governor Ogle to resolve the situation. Rioting broke out in the disputed territory and Ogle appealed to the King for resolution.[5]

Faced with this situation, Charles sailed to Maryland and personally assumed charge of the colony in 1732, becoming for a brief period governor in his own right.[5] His purpose in undertaking the long journey was chiefly to settle the dispute with Pennsylvania, as well as to attend to other pressing matters.[6] Violence had broken out on the border with Pennsylvania, with Maryland loyalists such as Thomas Cresap engaging in violent exchanges with hostile Pennsylvanians.[7]

Unfortunately for the Marylanders, Charles unwittingly agreed to a settlement of the territorial dispute with Pennsylvania, based on an inaccurate map, using calculations of latitude and longitude which were either wrong or were deliberately omitted.[8] Upon realizing the scale of his deception, Lord Baltimore reneged on the agreement, but in 1735 The Penns brought proceedings in the Court of Chancery in London to enforce compliance.[8] Chancery proceedings were notoriously slow and a final verdict was not reached until 1750, when Lord Chancellor Hardwicke found in favour of the claims of the Pennsylvanians in every respect.[8] Charles's error ultimately resulted in the loss to Pennsylvania of approximately one thousand square miles of Maryland territory.

In 1732 Calvert returned to England, again leaving the government of Maryland in the hands of Governor Samuel Ogle, and pursued a successful career in English politics. He was a Fellow of the Royal Society and a friend of fourth-cousin, Frederick Louis who was Prince of Wales and the eldest son of King George II of Great Britain. He was Gentleman of the Bedchamber to the Prince of Wales between 1731 and 1747.

In 1739 he sailed on his new yacht Augusta for Russia to represent the British Royal Family at the marriage of Grand Duchess Anna Leopoldovna of Russia to Anthony Ulrich, Duke of Brunswick-Lüneburg.[9] The union, designed to strengthen the relationships between the houses of Romanov and Habsburg, was celebrated in grand style. Francesco Algarotti, the Italian polymath accompanied Calvert and sent detailed accounts of the journey to and from St Petersburg to his friend Lord Hervey.[10] Also in the party were mathematician Erasmus King, and young Thomas Desaguliers, son of Dr John Theophilus Desaguliers.

Baltimore was elected Member of Parliament (MP) for St Germains, a rotten borough in Cornwall, from 1734 to 1741, and was MP for Surrey from 1741 to 1751. He was Lord of the Admiralty[11] from 1742 to 1744, and from 1747 to 1751 he was Surveyor-General of the Duchy of Cornwall. In addition he was Cofferer of the Household to the Prince of Wales from 1747 to 1751.

Calvert was able to sit in the House of Commons as a member of the Irish peerage. 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.

George II said of Charles Calvert: "there is my Lord Baltimore, who thinks he understands everything, and understands nothing: who wants to be well with both Courts and is well with neither, and who, entre nous, is a little mad."