The "National Institution for the Preservation of Life from Shipwreck" is founded in the United Kingdom, later to be renamed The Royal National Lifeboat Institution in 1858.

The British Parliament abolishes feudalism and the seigneurial system in British North America.

Uruguay is formally proclaimed independent at preliminary peace talks brokered by Great Britain between Brazil and Argentina during the Argentina-Brazil War.

Charles Fremantle arrives in the ''HMS Challenger'' off the coast of modern-day Western Australia prior to declaring the Swan River Colony for the United Kingdom.

In the face of fierce opposition, British governor Lord William Bentinck issues a regulation declaring that all who abet suttee in India are guilty of culpable homicide.

The United Kingdom legislates the abolition of slavery in its empire.

The British colonies abolish slavery.

The Patriots of Lower Canada (Quebec) rebel against the British for freedom.

The United Kingdom captures Hong Kong as a base as it prepares for war with Qing China. The ensuing 3-year conflict will later be known as the First Opium War.

Signing of the Treaty of Waitangi, establishing New Zealand as a British colony.

The transporting of British convicts to the New South Wales colony is abolished.

Hong Kong Island is occupied by the British.

The United Kingdom formally occupies Hong Kong, which China later formally cedes.

The Sultan of Brunei cedes Sarawak to the United Kingdom.

Ka Lā Hui: Hawaiian Independence Day – The Kingdom of Hawaii is officially recognized by the United Kingdom and France as an independent nation.

The United States House of Representatives votes to stop sharing the Oregon Territory with the United Kingdom.

Neptune is discovered by French astronomer Urbain Jean Joseph Le Verrier and British astronomer John Couch Adams; the discovery is verified by German astronomer Johann Gottfried Galle.

Corn Laws are abolished in the United Kingdom (following legislation in 1846).

The United Kingdom annexes the Punjab.

The United Kingdom recognizes the independence of the Boer colonies of the Transvaal.

The United Kingdom recognizes the independence of the Orange Free State.

Crimean War: The United Kingdom declares war on Russia.

Battle of Alma: British and French troops defeat Russians in the Crimea.

Second Opium War: France and the United Kingdom declare war on China.

British and French engineers break ground for the Suez Canal.

Pig War: Ambiguity in the Oregon Treaty leads to the "Northwestern Boundary Dispute" between U.S. and British/Canadian settlers.

In the Second Opium War, an Anglo-French force defeats Chinese troops at the Battle of Baliqiao.

The first British seagoing iron-clad warship, HMS ''Warrior'' is launched.

The United Kingdom annexes Lagos, Nigeria.

American Civil War: The "Trent Affair" – The USS San Jacinto stops the United Kingdom mail ship Trent and arrests two Confederate envoys, sparking a diplomatic crisis between the UK and US.

American Civil War: The ''Trent Affair'': Confederate diplomatic envoys James M. Mason and John Slidell are freed by the United States government, thus heading off a possible war between the United States and Britain.

The Anglo-Satsuma War begins between the Satsuma Domain of Japan and the United Kingdom (Traditional Japanese date: July 2, 1863).

In the Fenian Invasion of Canada, John O'Neill leads 850 Fenian raiders across the Niagara River at Buffalo, New York/Fort Erie, Ontario, as part of an effort to free Ireland from the United Kingdom. Canadian militia and British regulars repulse the invaders in over the next three days, at a cost of 9 dead and 38 wounded to the Fenian's 19 dead and about 17 wounded.

At Arogee in Abyssinia, British and Indian forces defeat an army of Emperor Tewodros II. While 700 Ethiopians are killed and many more injured, only two die from the British/Indian troops.

The Abyssinian War ends as British and Indian troops capture Magdala.

The crewless American ship ''Mary Celeste'' is found by the British brig ''Dei Gratia'' (the ship had been abandoned for nine days but was only slightly damaged).

Japan launches its postal savings system, modeled after a similar system in the United Kingdom.

The United Kingdom annexes the Transvaal.

Cyprus Convention: The Ottoman Empire cedes Cyprus to the United Kingdom but retains nominal title.

Russia and the United Kingdom sign the Treaty of Gandamak establishing an Afghan state.