|Covid-19|Monarch - George III
Prime Minister - William Cavendish-Bentinck, 3rd Duke of Portland (Tory) (until 4 October), Spencer Perceval (Tory) (starting 4 October)
5 January - The Treaty of the Dardanelles between the United Kingdom and the Ottoman Empire is concluded.
16 January - Peninsular War: Battle of Corunna in Galicia (Spain): The British (under General Sir John Moore, who is killed) resist an attempt by the French (under Marshal Soult) to prevent them embarking.
22 January - Royal Navy brig-sloop HMS Primrose (1807) (bound for the Peninsular War) is wrecked in a snowstorm on The Manacles reef off The Lizard peninsula in Cornwall with only a drummer boy surviving and the transport Dispatch is wrecked on Black Head nearby with 104 homeward bound soldiers lost and only seven survivors.
1 March - The literary and political periodical The Quarterly Review is first published by John Murray.
18 April - First running of the 2,000 Guineas Stakes horse race at Newmarket, won by Wizard.
22 April - General Sir Arthur Wellesley arrives at Lisbon onboard HMS Surveillante to take command of the British troops in Portugal.
10–11 May - Peninsular War: Battle of Grijó: the Anglo-Portuguese Army commanded by Sir Arthur Wellesley defeats the French army commanded by Marshal Soult in Portugal.
12 May - Peninsular War: Second Battle of Porto: the Anglo-Portuguese Army commanded by Wellesley crosses the Douro, drives the French army commanded by Marshal Soult out of Porto and forces them to retreat into Spain.
24 May - Dartmoor Prison opens, to house French prisoners of war.
19 June - Law passed to prevent blatant sale of seats in the House of Commons to supporters.
7 June - Shoja Shah of Afghanistan signs a treaty with the British. Only weeks later, he is succeeded by Mahmud Shah.
27–28 July - Wellesley's British, Portuguese, and Spanish army defeats a much larger French force at the Battle of Talavera in Spain.
30 July - British invasion army lands in Walcheren.
30 July–9 December - United Kingdom defeated in the Walcheren Campaign in the Netherlands.
4 September - Wellesley is appointed Baron Douro and Viscount Wellington in the peerage of the United Kingdom.
18 September - A new Theatre Royal, Covent Garden (pictured) opens in London to replace the first burnt down in 1808. An increase in ticket prices causes the Old Price Riots which last for 64 days.
4 October - Portland resigns due to ill health; Spencer Perceval takes over as Prime Minister.
21 October - Nelson's Pillar in Dublin is completed.
25 October - Statue of Horatio Nelson by Richard Westmacott, erected by public subscription, is unveiled in Birmingham, the first statue of Admiral Lord Nelson in the country.
10 November - The Berners Street Hoax: Theodore Hook manages to attract dozens of people to 54 Berners Street in London.
25 November - Benjamin Bathurst, a British diplomat, mysteriously disappears (having possibly been murdered) in Perleberg, west of Berlin.
26 December - British invasion force leaves Vlissingen.
Napoleonic Wars, 1803–1815
Anglo-Russian War, 1807–1812
Peninsular War, 1808–1814
"Preventive Water Guard", forerunner of Her Majesty's Coastguard, formed.
Jenny Pipes becomes the last woman in England to suffer punishment in the ducking stool for being a common scold, in Leominster.
William Combe begins publication of the verse Tour of Dr Syntax in search of the Picturesque in Ackermann's Political Magazine, illustrated by Thomas Rowlandson.
12 February - Charles Darwin, naturalist (died 1882)
7 April - James Glaisher, meteorologist and aeronaut (died 1903)
4 June - John Henry Pratt, clergyman and mathematician (died 1871)
6 August - Alfred Lord Tennyson, poet (died 1892)
27 November - Fanny Kemble, British-born American actress and writer (died 1893)
29 December - William Ewart Gladstone, Prime Minister of the United Kingdom (died 1898)
date unknown - Evan James, lyricist of the Welsh national anthem
16 January - John Moore, British general (killed in battle) (born 1761)
20 February - Richard Gough, antiquary (born 1735)
25 February - John Murray, 4th Earl of Dunmore (born 1730)
11 March - Hannah Cowley, dramatist, poet and social reformer (born 1743)
25 March - Anna Seward, writer (born 1747)
April - Charles Francis Greville, founder of Milford Haven, 59 (born 1749)
13 May - Beilby Porteus, bishop and abolitionist (born 1731)
21 June - Daniel Lambert, the fattest man in Britain, weighing 52 stones 11 pounds, died in Stamford, Lincolnshire (born 1770)
18 August - Matthew Boulton, manufacturer and engineer (born 1728)
8 October - James Elphinston, philologist (born 1721)
30 October - William Cavendish-Bentinck, 3rd Duke of Portland, Prime Minister of the United Kingdom (born 1738)
9 November - Paul Sandby, cartographer and painter (born 1725)
1809 in the United Kingdom Wikipedia
Events from the year 1809 in the United Kingdom.