He married Kathleen Belcher in 1926 and they had two sons, John and George Forester. The couple divorced in 1945. In 1947, he married Dorothy Foster. John Forester wrote a two-volume biography of his father, including many elements of Forester’s life which only became clear to his son after his death.

Forester wrote many novels, but he is best known for the 12-book Horatio Hornblower series depicting a Royal Navy officer during the Napoleonic Wars. He began the series with Hornblower fairly high in rank in the first novel that he wrote, which was published in 1937. But high demand for more stories led him to fill in Hornblower’s life story, and he wrote novels detailing his rise from the rank of midshipman. The last completed novel was published in 1962. Hornblower’s fictional feats were based on real events, but Forester wrote the body of the works carefully to avoid entanglements with real world history, so that Hornblower is always off on another mission when a great naval battle occurs during the Napoleonic Wars.

Forester moved to the United States during the Second World War, where he worked for the British Ministry of Information and wrote propaganda to encourage the US to join the Allies. He eventually settled in Berkeley, California. He met Roald Dahl in 1942 while living in Washington, D.C., and Forester encouraged him to write about his experiences in the RAF. According to Dahl’s autobiography Lucky Break, Forester asked him about his experiences as a fighter pilot, and this prompted Dahl to write his first story “A Piece of Cake”.

Forester appeared as a contestant on the television quiz programme You Bet Your Life hosted by Groucho Marx, in an episode broadcast on 1 November 1956. A previously unknown novel of Forester’s entitled The Pursued was discovered in 2003 and published by Penguin Classics on 3 November 2011.