A Ship of the Line is an historical seafaring novel by C. S. Forester. It follows his fictional hero Horatio Hornblower during his tour as captain of a ship of the line. By internal chronology, A Ship of the Line, which follows The Happy Return, is the seventh book in the series (counting the unfinished Hornblower and the Crisis). However, the book, published in 1938, was the second Hornblower novel completed by Forester. It is one of three Hornblower novels adapted into the 1951 British-American film Captain Horatio Hornblower R.N..