- As Sophia, Electress of Hanover, had died two months before Queen Anne (who died in 1714), Sophia's eldest son George, Elector of Hanover, inherited the throne under the Act of Settlement (there were some 50 Roman Catholic relatives with stronger claims). His claim was challenged by James Stuart, Roman Catholic son of James II, who landed in Scotland in 1715, following a rising of Scottish clans on his behalf; this was unsuccessful and he soon withdrew.
George I (reigned 1714-27) spoke German and French and a little English; he regularly visited Hanover to fulfil his duties there. Family tensions (George imprisoned his wife in 1694) and political intrigue (opposition gathered round the Prince of Wales) led to differences and intense dislike between George and his son, George. In 1719 and 1720, and during most of the king's absences in Hanover, power was delegated to a Regency Council and not to the Prince of Wales. Unfamiliar with the customs of the country, George was dependent on his ministers - the Whigs dominated Parliament during his reign.
After the South Sea Bubble crisis of 1720 (when the South Sea Company, with heavy government and royal investments, crashed), Robert Walpole took over. The most able of George's ministers, and known as the first 'Prime Minister', Walpole's was the longest running administration in British history (1721-42). George died in 1727, during a visit to Hanover.
REF: The British Monarchy Official Website