The eldest son of Thomas Latham, vicar of Billingborough, Lincolnshire, he was born there on 24 March 1812.
[1][2] Latham studied philology for a year on the continent, near Hamburg, then in Copenhagen with Rasmus Christian Rask,[3] and finally in Christiania (now Oslo).
[2] Here he associated with Thomas Hewitt Key and Henry Malden, linguists working in the tradition of Friedrich August Rosen.
Together they developed the Philological Society, expanding it from a student group to a broad base among London philologists, publishing its own Proceedings.
[5] Latham decided to enter the medical profession, and in 1842 became a licentiate of the Royal College of Physicians; he subsequently obtained the degree of M.D.
[2] The origin of the Indo-European languages was, in Latham's view, in Lithuania; and he strongly attacked Max Müller, proponent of the "Aryan theory", at the same time as did John Crawfurd arguing from rather different premises.
[10] The controversy over Latham's views on Indo-European languages following his Comparative Philology (1862) did permanent damage to his scholarly reputation.
His works on the English language passed through many editions, and were regarded as authoritative till they were superseded by those of Richard Morris and Walter William Skeat.