Cowell was born in Ipswich, and became interested in Oriental languages at the age of fifteen, when he found a copy of Sir William Jones"s works (including his Persian Grammar) in the public library. On the death of his father in 1842 he took over the family business.
He married in 1845, and in 1850 entered Magdalen College, Oxford, where he studied and catalogued Persian manuscripts for the Bodleian Library.
Self-taught, he began translating and publishing Hafez within the year. From 1856-1867 he lived in Calcutta as professor of English history at Presidency College. He was also as principal of Sanskrit College from 1858 to 1864.
He also published, unsigned, an introduction to Khayyám with translations of thirty quatrains in the Calcutta Review (1858).
Having studied Hindustani, Bengali, and Sanskrit with Indian scholars, he returned to England to take up an appointment as the first professor of Sanskrit at Cambridge. He was professor from 1867 until his death in 1903.
