He was born at Kinnaird, Perthshire and brought up by his grandfather from the age of three as a result of his parents and younger brother emigrating to America. Illiterate until the age of 13 he showed no early signs of linguistic ability, but despite this late start at age 17 he was appointed schoolmaster of the village of Stralock.
Shortly after this he attended Kirkmichael school followed by Perth Grammar School and the University of St. Andrews gaining a Masters degree from the later.
In 1823 he took a post at Calcutta Academy, but due to poor health he was forced to return to England in 1826. In 1837 he became Professor of Oriental Languages at King's College London and stayed at this post until his retirement in 1861. During his time at King's College London he also worked at the British Museum cataloguing their collection of Persian manuscripts.
During his life he wrote a number of books, and it is for these which he is most remembered.
see also Cox-Forbes theory