He was intended for the army, and entered at Sandhurst, but receiving no commission, he left his country and joined the Mexican navy. He served in the war against Spain, and underwent many adventures. Returning to England, he became a journalist, and in 1836-1837 edited The Monthly Repository. In 1837 he published two tragedies, Cosmo de' Medici and The Death of Marlowe, and in 1841 a History of Napoleon.
The book, however, by which he lives is his epic of Orion, which appeared in 1843. It was published originally at a farthing, was widely read, and passed through many editions. In the next year he set forth a volume of critical essays called A New Spirit of life Age, in which he was assisted by Elizabeth Barrett Browning, with whom, from 1839 to her marriage in 1845, he conducted a voluminous correspondence.
In 1852 he went to Australia in company with William Howitt, and did not return to England until 1869. He received a Civil List pension in 1874, and died at Margate on the 13th of March 1884.
Horne possessed extraordinary versatility, but, except in the case of Orion, he never attained to a very high degree of distinction. That poem, indeed, has much of the quality of fine poetry; it is earnest, vivid and alive with spirit. But Horne early drove his talent too hard, and continued to write when he had little left to say. In criticism he had insight and quickness. He was one of the first to appreciate Keats and Tennyson, and he gave valuable encouragement to Mrs Browning when she was still Miss Elizabeth Barrett.