Background
Anstruther-Thomson was the son of Colonel John Anstruther and Grizel Maria Thomson of Charleton in Fife, Scotland. He married Clementina Blair, daughter of William Blair of Blair Adam and Honorable Eleanor Elphinstone, on 27 April 1807.
Anstruther-Thomson was the son of Colonel John Anstruther and Grizel Maria Thomson of Charleton in Fife, Scotland. He married Clementina Blair, daughter of William Blair of Blair Adam and Honorable Eleanor Elphinstone, on 27 April 1807.
Joing the Royal Fifeshire Yeomanry Cavalry he took over command from Lieutenant Colonel Morison of Naughton in 1809 and continued in command until 1823. Under his command the Regiment flourished, receiving in 1814 the thanks of both Houses of Parliament for its services. He was baptised with the name of John Anstruther but in 1815 his name was legally changed to John Anstruther-Thomson to inherit the Charleton Estate from his mother"s family.
He succeeded to the title of 17th Lord Saint Clair on 5 July 1795 but did not take this title.