"The Conqueror" (1931) was Heyer's first novel of historical fiction to give a fictionalized account of real historical events. She researched the life of William the Conqueror thoroughly, even travelling the route that William took when crossing into England. The following year, Heyer's writing took an even more drastic departure from her early historical romances when her first thriller, "Footsteps in the Dark" was published. The novel's appearance coincided with the birth of her only child, Richard George Rougier, whom she called her "most notable (indeed peerless) work". Later in her life, Heyer requested that her publishers refrain from reprinting "Footsteps in the Dark", saying "This work, published simultaneously with my son ... was the first of my thrillers and was perpetuated while I was, as any Regency character would have said, increasing. One husband and two ribald brothers all had fingers in it, and I do not claim it as a Major Work."