Thomson, George (1799–1886), military and railway engineer, was born 19 September 1799 at Fairley, Aberdeenshire, Scotland, second son of George Thomson and his wife Agnes (née Dingwall). Initially educated by private tutor, he entered the East India Company's military college at Addiscombe (1814) and was commissioned ensign in the Bengal Engineers (1818). Arriving in India in September 1818, he was posted to Allahabad and employed on the construction of several roads. In September 1823 he was promoted to lieutenant and took part in the first Burma war (1824–6), commanding the engineers and pontoon section and taking part in the attacks on Paddowa and Mahatee. He was prominent in the final assault on Arracan (April 1825) and was mentioned in dispatches.
On his return to India he was appointed executive engineer of the public works in the department of Nimach and was promoted captain (September 1827). After further service on road construction projects and also survey expeditions, he was appointed to command the Bengal Engineers detachment at Delhi while also serving as executive engineer of the local public works department (March 1837–September 1838). In September 1838 he was chosen to command the engineer detachment of the Army of the Indus, which was preparing to invade Afghanistan. Reaching the River Indus in January 1839, he supervised its bridging, for which he was later mentioned in general orders. He prepared a road for the army through the Bolan Pass and over the Amran mountains, and was present at the capture of Kandahar. When the army reached the fortress of Ghazni (Ghuznee), Thomson reconnoitred its defences and prepared a plan of attack for the expedition's commander, Gen. Sir John (later Lord) Keane (1781–1844). He took part in the assault on the fortress on 23 July 1839 and was one of the party that captured the Kabul gate, again being mentioned in Keane's dispatches. Promoted to brevet major for his conduct during the storming of Ghazni, he took part in the capture of Kabul. In December 1839 he was made a CB for his services in Afghanistan and was awarded the Order of the Durani Empire by Shah Suja of Afghanistan. He later wrote an account of the storming of Ghazni which was published in Professional papers of the Corps of Royal Engineers in 1840. Returning to India, he was reappointed executive engineer of the Delhi public works division in November 1839, retiring from the service in January 1841.
Thomson entered into a business venture with his brother in Liverpool, which failed, and in July 1844 he was appointed by the East India Company as paymaster of pensions and recruiting officer for the Cork district, with the rank of major. He soon became a popular figure in Cork and was known as ‘Ghazni Thomson’. In 1846 he was appointed a director of the Great Southern & Western Railway, largely due to the influence of his brother-in-law, William Taylor (qv), who was the company's secretary. He also served as a superintending engineer for the company, overseeing the construction of new branch lines and supervising the building of bridges and tunnels. During his time as a director of the GSWR, several branch lines were completed and he supervised the completion of the southern section of the line and the construction of the tunnel into Cork city. In 1854 he was made a brevet colonel, and was promoted to honorary colonel in October 1877. In 1877 he resigned as paymaster of the Cork district and moved to Dublin, but continued to carry out some work for the GSWR. He died 11 February 1886 at his Dublin residence, 33 Leeson Park.
He married (1830) Anna Dingwall of Ramieston, Aberdeenshire; they had several children. His eldest son, Hugh Gordon (d. 1910), was later a major-general of the Indian army staff corps.