Born at Glasgow, Scotland, he was educated at the Glasgow high school, and when only sixteen obtained an ensigncy in the oth foot, through the influence of Colonel Campbell, his maternal uncle. His opportunity of engaging in active service soon came. He fought under Sir Arthur Wellesley at the Battle of Vimiera, took part in the retreat of Sir John Moore, and was present at the Battle of Corunna. He shared in all the fighting of the Peninsular campaigns, and was severely wounded while leading a storming-party at the attack on San Sebastian. He was again wounded at the passage of the Bidassoa, and compelled to return to England, when his conspicuous gallantry was rewarded by promotion.
Campbell held a command in the American expedition of 1814; and after the peace of the following year he devoted himself to studying military science. In 1823 he quelled the insurrection in Demerara, and two years later bought himself a major's rank. In 1832 he became lieutenant-colonel of the 98th foot, and with that regiment rendered distinguished service in the Chinese War of 1842. Campbell was next employed in the Sikh War of 1848-49, under Lord Gough. At Chillianwalla, where he was wounded, and at the decisive victory of Gujrat, his skill and valour largely contributed to the success of the British arms; and his "steady coolness and military precision" were highly praised in official despatches. He was made a K.C.B in 1849, and specially named in the thanks of parliament.
After rendering important services in India Sir Colin Campbell returned home in 1853. Next year the Crimean War broke out, and he accepted the command of the Highland brigade, which formed part of the Duke of Cambridge's division. The brigade and its leader distinguished themselves very greatly at the Battle of Alma; and with his "thin red line" of Highlanders he repulsed the Russian attack on Balaklava. At the close of the war Sir Colin was promoted to Knight Grand Cross of the Bath, and elected honorary D.C.L. of Oxford.
His military ability had been late in being recognised; but his true worth was soon appreciated. The outbreak of the Indian Mutiny called for a general of tried experience; and on July 11 1857 the command was offered to him by Lord Palmerston. On being asked when he would be ready to set out, Campbell replied, "Within twenty-four hours." He left England the next evening, and reached Calcutta on August 13. After spending over two months in the capital to organize his resources, he started for the front on October 27, and on November 17 relieved Lucknow for the second time. Sir Colin, however, considered Lucknow a false position, and once more abandoned it to the rebels, retaking it in March 1858. He continued in charge of the operations in Oudh until the embers of the revolt had died away. For these services he was raised to the peerage, in 1858, as Baron Clyde; and, returning to England in the next year, he received the thanks of both Houses of Parliament and a pension of £2000 a year.
Though not a great general, and lacking the dash which won England so many victories in India, Lord Clyde was regarded as a brave soldier and a careful and prudent leader. The soldiers whom he led were devotedly attached to him; and he commanded unvarying respect.
See Sir Owen Tudor Burne, Clyde and Siratlinairn ("Rulers of India" series, 1891); and L Shadwell, Life of Cohn Campbell, Lord Clyde (1881).