Colborne was deployed with his regiment to Italy where he distinguished himself at the Battle of Maida in July 1806 during the War of the Third Coalition.[2] He became military secretary to General Henry Fox in 1806 and then became military secretary to Sir John Moore with the rank of major on 21 January 1808.[2] In this capacity he accompanied Moore to Sweden in May 1808 and to Portugal in 1808 and served with him at the Battle of Benavente in December 1808 and Battle of Corunna in January 1809.[2] It was Moore's dying request that Colborne should be given a lieutenant colonelcy and this was complied with on 2 February 1809.[2] He transferred to the 66th Regiment of Foot on 2 November 1809, and after returning to Spain with Sir Arthur Wellesley's Army, he witnessed the defeat of the Spaniards at the Battle of Ocaña later that month.[4] He commanded a brigade at the Battle of Bussaco in September 1810 and then commanded the 2nd Battalion of the 66th Regiment of Foot at the Battle of Albuera in May 1811 where his brigade was virtually annihilated by the Polish 1st VistulanLancers Regiment of the French Army.[5] After transferring to the command of the 52nd Regiment of Foot he took part in the Siege of Ciudad Rodrigo in January 1812 where he was badly injured and had to be invalided back to England.[4]
Colborne became aide-de-camp to the Prince Regent with the rank of colonel on 4 June 1814,[7] and, following Napoleon's escape from Elba, he managed to dissuade the Prince from attacking the French Army until the Duke of Wellington arrived.[4]
At the Battle of Waterloo in June 1815 during the Hundred Days, Colborne led the 52nd Regiment of Foot. At the critical moment of the battle, when the French Imperial Guard attacked Welligton's weakened centre, Colborne made a decisive intervention. On his own initiative, Colborne brought the 52nd Regiment of Foot forward, took up a flanking position in relation to the Imperial Guard and then, after firing repeated volleys into their flank, charged at the Guard so driving them back in disorder.[1] As soon as General Sir Frederick Adam saw what Colborne was doing, he sent in extra troops to support him.[8] Colborne drove forward towards La Haye Sainte, while Wellington rode back to the main line to order the general advance.[9]
He was appointed a Knight of the Austrian Military Order of Maria Theresa on 2 August 1815.[10] After the war he remained with his regiment as part of the Army of Occupation.[5]
In August 1828 Colborne was appointed Lieutenant Governor of Upper Canada.[13] As Lieutenant Governor, Colborne increased the population of the province by 70% by initiating an organised system of immigration to bring in settlers from Britain.[5] He also aided settlement by expanding the communication and transportation infrastructure through a campaign to build roads and bridges.[1] He brought changes to the structure of the legislative council, increased fiscal autonomy and encouraged greater independence in the judiciary.[1] In 1829 he founded Upper Canada College as a school based on the Elizabeth College, Guernsey model to educate boys in preparation for becoming leaders of the colonies.[1]
During Colborne's period of office as commander-in-chief, the Family Compact promoted resistance to the political principle of responsible government.[15] At the end of its lifespan, the Compact would be condemned by Lord Durham as "a petty corrupt insolent Tory clique".[15] In both Upper Canada, which was under Colborne's administration, and Lower Canada, which was under the direct administration of Colborne's superior, Governor General Lord Gosford, this resistance to responsible government, together with conflicts between the assembly and the executive over fiscal matters, as well as a difficult economic situation, led to the Rebellions of 1837.[1]
In January 1836 Colborne became commander-in-chief of all the armed forces in British North America.[1] He was promoted to the local rank of lieutenant general on 8 July 1836.[16] Colborne personally led the offensive at the Battle of Saint-Eustache in December 1837 defeating the rebel force which had become holed up in a church. His forces burnt the church and set fire to surrounding buildings. Afterwards, he led the sack of the nearby village of Saint-Benoît, burning much of the village. The French-Canadians gave him the nickname "Le vieux brûlot" ("the old fire-breather").[1][17]
Colborne was advanced to Knight Grand Cross of the Order of the Bath on 29 January 1838.[18] Following Lord Gosford's resignation in February 1838, he became acting Governor General of British North America.[1] In Lower Canada but not Upper Canada, the 1791 constitution was suspended at this time, causing the colony's bicameral parliament to be dissolved. To replace these bodies and assist in governing Lower Canada, Colborne established a 24-member Special Council.[1]
Colborne stepped aside as acting Governor General until the arrival of Gosford's formal successor, Lord Durham, on 27 May 1838. Colborne was promoted to the substantive rank of lieutenant-general on 28 June 1838.[19] Durham remained in Canada only for a few months, resigning on 9 October and leaving for London on the fifth-rate HMS Inconstant on 1 November,[20] after he learned that his policy of leniency towards the leaders of the prior year's rebellion had been repudiated by the British Government. Durham's departure caused Colborne to again become acting Governor General. Colborne put down a second revolt in November and was confirmed as Governor General of British North America on 14 December.[21] He left Canada in October 1839 after the arrival of his successor, Charles Poulett Thomson (who shortly thereafter would be elevated to the peerage as Lord Sydenham). After arriving back in England, Colborne was himself elevated to the peerage as Baron Seaton, of Seaton in the County of Devon, on 5 December 1839.[22]
An Act to settle an Annuity on Lord Seaton and the Two next surviving Heirs Male of the Body of the said Lord Seaton to whom the Title of Lord Seaton shall descend in consideration of his important Services.
In recognition of the "important services" rendered by Colborne, and following a message from Queen Victoria,[23]Parliament settled an annuity of £2,000 on him and the next two heirs male who would succeed to the title.[24]
^Priddis, Harriet (1908). "Naming of London Streets". Historic Sketches of London Ontario. London, Ontario: The London and Middlesex Historical Society. p. 20. Colborne Street, named for Sir John Colborne, Governor of Canada West during the troublesome times that preceded the Rebellion.