The siege of Havana was a successful British siege against Spanish-ruled Havana that lasted from March to August 1762, as part of the Seven Years' War. After Spain abandoned its former policy of neutrality by signing the family compact with France, resulting in a British declaration of war on Spain in January 1762, the British government decided to mount an attack on the important Spanish fortress and naval base of Havana, with the intention of weakening the Spanish presence in the Caribbean and improving the security of its own North American colonies. A strong British naval force consisting of squadrons from Britain and the West Indies, and the military force of British and American troops it convoyed, were able to approach Havana from a direction that neither the Spanish governor nor the Admiral expected and were able to trap the Spanish fleet in the Havana harbour and land its troops with relatively little resistance.

The Spanish authorities decided on a strategy of delaying the British attack until the strength of the city's defences and the onset of seasonal rains inflicting tropical diseases would significantly reduce the size of the British force via disease, along with the start of hurricane season would force the British fleet to seek a safe anchorage. However, the city's main fortress, the Morro Castle was overlooked by a hill that the governor had neglected to fortify; the British installed batteries there and bombarded the fortress daily with heavy shelling. The fortress eventually fell after the officer in charge of Morro Castle, Luis Vicente de Velasco, was mortally wounded by a stray bullet. The capture of Morro Castle led to the eventual fall of the rest of the fortifications and the surrender of the city, the remaining garrison, and the naval forces present, before the hurricane season began.

The surrender of Havana led to substantial rewards for the British naval and military leaders and smaller amounts of prize money for other officers and men. The Spanish governor, Admiral and other military and civil office holders were court-martialled upon their return to Spain and punished for their failures to conduct a better defence and allowing the Spanish fleet present to fall intact into the hands of the British. Havana remained under British occupation until February 1763, when it was returned to Spain under the 1763 Treaty of Paris that formally ended the war.

The Kingdom of Great Britain, officially called Great Britain, was a sovereign country in Western Europe from 1 May 1707 to 31 December 1800. The state was created by the 1706 Treaty of Union and ratified by the Acts of Union 1707, which united the kingdoms of England (which included Wales) and Scotland to form a single kingdom encompassing the whole island of Great Britain and its outlying islands, with the exception of the Isle of Man and the Channel Islands. The unitary state was governed by a single parliament at the Palace of Westminster, but distinct legal systems – English law and Scots law – remained in use.

The formerly separate kingdoms had been in personal union since the 1603 "Union of the Crowns" when James VI of Scotland became King of England and King of Ireland. Since James's reign, who had been the first to refer to himself as "king of Great Britain", a political union between the two mainland British kingdoms had been repeatedly attempted and aborted by both the Parliament of England and the Parliament of Scotland. Queen Anne (r. 1702–1714) did not produce a clear Protestant heir and endangered the line of succession, with the laws of succession differing in the two kingdoms and threatening a return to the throne of Scotland of the Roman Catholic House of Stuart, exiled in the Glorious Revolution of 1688.

The resulting kingdom was in legislative and personal union with the Kingdom of Ireland from its inception, but the Parliament of Great Britain resisted early attempts to incorporate Ireland in the political union. The early years of the newly united kingdom were marked by Jacobite risings, particularly the Jacobite rising of 1715. The relative incapacity or ineptitude of the Hanoverian kings resulted in a growth in the powers of Parliament and a new role, that of "prime minister", emerged in the heyday of Robert Walpole. The "South Sea Bubble" economic crisis was brought on by the failure of the South Sea Company, an early joint-stock company. The campaigns of Jacobitism ended in defeat for the Stuarts' cause in 1746.

The Hanoverian line of monarchs gave their names to the Georgian era and the term "Georgian" is typically used in the contexts of social and political history for Georgian architecture. The term "Augustan literature" is often used for Augustan drama, Augustan poetry and Augustan prose in the period 1700–1740s. The term "Augustan" refers to the acknowledgement of the influence of classical Latin from the ancient Roman Republic.Victory in the Seven Years' War led to the dominance of the British Empire, which was to become the foremost global power for over a century. Great Britain would dominate the Indian subcontinent through the trading and military expansion of the East India Company in colonial India. In wars against France, it gained control of both Upper and Lower Canada, and until suffering defeat in the American War of Independence, it also had dominion over the Thirteen Colonies. From 1787, Britain began the colonisation of New South Wales with the departure of the First Fleet in the process of penal transportation to Australia. Britain was a leading belligerent in the French Revolutionary Wars.

Great Britain was merged into the United Kingdom of Great Britain and Ireland on 1 January 1801, with the Acts of Union 1800, enacted by Great Britain and Ireland, under George III, to merge with it the Kingdom of Ireland.