Question: What profession does Anne Perry and Bernard Cornwell have in common?

<P0-S0> Sharpe's Peril is a British TV film from 2008, usually shown in two parts, which is part of an ITV series based on Bernard Cornwell's historical fiction novels about the English soldier Richard Sharpe during the Napoleonic Wars. <P0-S1>  Contrary to most parts of the TV series, "Sharpe's Peril" isn't based on one of Cornwell's novels. <P0-S2>  Both are set in 1817, two years after Sharpe has retired as a farmer in Normandy, so chronologically they come after "Sharpe's Waterloo" (1815) and before the final novel "Sharpe's Devil" (1820–21). <P0-S3>  In "Sharpe's Challenge" and "Sharpe's Peril", Sharpe and his comrade in arms, Patrick Harper, have been temporarily called out of retirement and asked to go to India. <SEP> <P1-S0> Sharpe's Challenge is a British TV film from 2006, usually shown in two parts, which is part of an ITV series based on Bernard Cornwell's historical fiction novels about the English soldier Richard Sharpe during the Napoleonic Wars. <P1-S1>  Contrary to most parts of the TV series, "Sharpe's Challenge", as well as the follow-up "Sharpe's Peril", isn't based entirely on one of Cornwell's novels, but it uses and adapts some characters and storylines from "Sharpe's Tiger". <P1-S2>  Both are set in 1817, two years after Sharpe has retired as a farmer in Normandy, so chronologically they come after "Sharpe's Waterloo" (1815) and before the final novel "Sharpe's Devil" (1820–21). <P1-S3>  Some of the events in the film are, however, inspired by events in the first three novels of the series. <P1-S4>  In "Sharpe's Challenge" and "Sharpe's Peril", Sharpe and his comrade in arms, Patrick Harper, have been temporarily called out of retirement and asked to go to India. <SEP> <P2-S0>  At the age of fifteen she was convicted of participating in the murder of her friend's mother, in 1954. <P2-S1> Anne Perry (born 28 October 1938 as Juliet Marion Hulme) is an English author of historical detective fiction, best known for her Thomas Pitt and William Monk series. <P2-S2>  She changed her name after serving her five-year sentence. <SEP> <P3-S0> Bernard Cornwell, OBE (born 23 February 1944) is an English author of historical novels and a history of the Waterloo Campaign. <P3-S1>  He is best known for his novels about Napoleonic Wars rifleman Richard Sharpe. <P3-S2>  Cornwell has written historical novels primarily of English history in five series and one series of contemporary thriller novels. <P3-S3>  A feature of his historical novels is an end note on how the novel matches or differs from history, for the re-telling, and what one might see at the modern site of the battles described in the novel. <P3-S4>  One series of historical novels is set in the American Civil War. <P3-S5>  He wrote a nonfiction book on the battle of Waterloo, in addition to the fictional story of the famous battle in the Sharpe Series. <P3-S6>  Two of the historical novel series have been adapted for television; the Sharpe television series by ITV and "The Last Kingdom" by BBC. <P3-S7>  He lives in the US with his wife. <P3-S8>  He alternates between Cape Cod, Massachusetts and Charleston, South Carolina.