Born in Edinburgh, Scotland, on May 22, 1859, Doyle was the son of an Irish painter who specialized in fantasy scenes. Doyle was sent to England at age nine to attend boarding school, an experience he deeply loathed. He then enrolled in medical school, after which he briefly served as a naval doctor before entering into private practice. He moved around southern England until he finally settled in the town of Southsea. Doyle had written for his own pleasure up until this point in his life but succeeded in publishing A Study in Scarlet in 1887, a slim novel that introduced the world to Sherlock Holmes.

Doyle wrote another Sherlock Holmes novel, The Sign of Four, in 1890, and moved with his wife, Louise, to London in 1891. By this time, Doyle had decided to become an eye doctor, especially because his first two Sherlock Holmes novels had not been financial successes. Ironically, however, Doyle found that he had few patients and was consequently left with plenty of time to write. By switching formats and writing Holmes mysteries as short stories rather than novels, Doyle was able to capitalize on his talent for writing rapid, engrossing plots and minimize some of the tedium that had plagued his earlier work. Serialized in the popular magazine, the Strand, Sherlock Holmes and his adventures became an overnight phenomenon, electrifying readers throughout the English-speaking world. “The Red-Headed League” first appeared in the Strand in 1891 and was published a year later with eleven other stories as The Adventures of Sherlock Holmes.

In a matter of months, Doyle went from a struggling eye doctor to one of the most famous writers in the world. He quickly grew tired of being solely identified with Holmes, however. So in 1893, he killed off his fictional detective in a climactic battle with the evil Professor Moriarity. Readers in Britain and the United States mourned the loss of their hero, and grown men were seen to wear black armbands for weeks afterward.

Doyle continued to write both fiction and nonfiction throughout the 1890s, although none of his works were as popular as the Sherlock Holmes stories. Hoping to boost his popularity and sales, Doyle revived Sherlock Holmes again in 1901 with The Hound of the Baskervilles, a novel many critics regard as one of the greatest mysteries ever written. In 1903, he began writing Holmes stories again and continued to do so almost until his death in 1930. In addition to many other works, he published The Lost World, a popular science-fiction novel, in 1912.

The success of the Sherlock Holmes stories can hardly be overstated. Almost single-handedly, Doyle inaugurated two massive changes in literature. First, he transformed the short story from a mildly successful exercise into a major literary form capable of sustaining both an enormous readership and a longstanding critical interest. Second, Doyle perfected and popularized the detective story, which went on to become the most popular new genre of fiction in the twentieth century. Previous writers such as Edgar Allen Poe had published short stories and mysteries before, but all had failed to energize readers to the degree that Doyle’s Holmes energized them. Readers also identified with Holmes’s real-world London and liked the fact that they had the opportunity to solve the mysteries along with the hero. Sherlock Holmes had become so popular that by the end of the twentieth century he’d appeared in more than 100 films, more than 700 radio dramas, and more than 2,000 stories and novels. Perhaps only Mickey Mouse rivals Holmes as the most recognizable fictional character of the past century.

Much of Doyle’s popularity today stems from his vivid description of late-Victorian London. From the defeat of Napoleon in 1815 to the start of World War I in 1914, Britain was the dominant military power in the world. As a result, London was both the world’s largest city and the center of the most extensive and powerful empire in history by the end of the nineteenth century. Victorian London was also a city of mystery: a place of dark fogs, horse-drawn carriages, and Jack the Ripper. In other words, even though London at the end of the nineteenth century was the de facto capital of the world, Londoners were still deeply interested in their city’s dark undercurrents. Readers today find this mix of power and mystery fascinating and share with Doyle’s contemporaries a love for the way in which the intellect of Sherlock Holmes cuts through the shadows, illuminating the darkness with pure reason.