The siege of Louisburg took place in 1745 when a New England colonial force aided by a British fleet captured Louisburg, the capital of the French province of Île-Royale (present-day Cape Breton Island) during the War of the Austrian Succession, known as King George's War in the British colonies.

The northern British colonies regarded Louisbourg as a menace, calling it the "American Dunkirk" due to its use as a base for privateers. There was regular, intermittent warfare between the French and the Wabanaki Confederacy on one side and the northern New England colonies on the other. For the French, the Fortress of Louisbourg also protected the chief entrance to Canada, as well as the nearby French fisheries. The French government had spent 25 years in fortifying it, and the cost of its defenses was reckoned at thirty million livres. Although the fortress's construction and layout was acknowledged as having superior seaward defences, a series of low rises behind them made it vulnerable to a land attack. The low rises provided attackers places to erect siege batteries. The fort's garrison was poorly paid and supplied, and its inexperienced leaders mistrusted them. The colonial attackers were also lacking in experience, but ultimately succeeded in gaining control of the surrounding defences. The defenders surrendered in the face of an imminent assault.

Louisbourg was an important bargaining chip in the peace negotiations to end the war, since it represented a major British success. Factions within the British government were opposed to returning it to the French as part of any peace agreement, but these were eventually overruled, and Louisbourg was returned, over the objections of the victorious British North Americans, to French control after the 1748 Treaty of Aix-la-Chapelle, in return for French concessions elsewhere.

The Battle of Culloden was the final confrontation of the Jacobite rising of 1745. On 16 April 1746, the Jacobite army of Charles Edward Stuart was decisively defeated by a British government force under Prince William Augustus, Duke of Cumberland, on Drummossie Moor near Inverness in the Scottish Highlands. It was the last pitched battle fought on British soil.

Charles was the eldest son of James Stuart, the exiled Stuart claimant to the British throne. Believing there was support for a Stuart restoration in both Scotland and England, he landed in Scotland in July 1745: raising an army of Scots Jacobite supporters, he took Edinburgh by September, and defeated a British government force at Prestonpans. The government recalled 12,000 troops from the Continent to deal with the rising: a Jacobite invasion of England reached as far as Derby before turning back, having attracted relatively few English recruits.

The Jacobites, with limited French military support, attempted to consolidate their control of Scotland, where by early 1746, they were opposed by a substantial government army. A hollow Jacobite victory at Falkirk failed to change the strategic situation: with supplies and pay running short and with the government troops resupplied and reorganised under the Duke of Cumberland, son of British monarch George II, the Jacobite leadership had few options left other than to stand and fight. The two armies eventually met at Culloden, on terrain that gave Cumberland's larger, well-rested force the advantage. The battle lasted only an hour, with the Jacobites suffering a bloody defeat; between 1,500 and 2,000 Jacobites were killed or wounded, while about 300 government soldiers were killed or wounded. While perhaps 5,000 – 6,000 Jacobites remained in arms in Scotland, the leadership took the decision to disperse, effectively ending the rising.

Culloden and its aftermath continue to arouse strong feelings. The University of Glasgow awarded the Duke of Cumberland an honorary doctorate, but many modern commentators allege that the aftermath of the battle and subsequent crackdown on Jacobite sympathisers were brutal, earning Cumberland the sobriquet "Butcher". Efforts were subsequently made to further integrate the Scottish Highlands into the Kingdom of Great Britain; civil penalties were introduced to undermine the Scottish clan system, which had provided the Jacobites with the means to rapidly mobilise an army.