Arthur Ignatius Conan Doyle was born in Edinburgh in 1859; his father, Charles Doyle, was an artist and draughtsman (and alcoholic), whilst his mother Mary, née Foley, was descended from Irish immigrants who kept a lodging house. The family's circumstances were poor but Doyle was educated at Stoneyhurst through the assistance of wealthier relatives. He entered Edinburgh University Medical School in 1876, where the analytic methods of Joseph Bell made a great impression on him and fed into the later character of Sherlock Holmes. He graduated MB CM in 1881, having interspersed his academic training with work as a doctor's assistant in Birmingham and service as ship's doctor on a Greenland whaler, and added to this an Edinburgh MD in 1885, on aspects of syphilis.
After service as a ship's surgeon and an attempt to settle as a general practitioner in Plymouth, Conan Doyle set up in practice in Southsea. He married Louise Hawkins, sister of one of his patients, in 1885. During these early years he was also writing fiction, both novels and short stories. In 1886 his most famous characters, Sherlock Holmes and Dr. Watson, appeared for the first time in the novel A Study in Scarlet.
In 1891 he moved to London, settling at Tenison Road, South Norwood. In his medical career he was attempting to become a specialist in eye conditions, but his writing career took over rapidly: the experiment of transferring Holmes and Watson to the short-story genre was a resounding success and doubled the circulation of the new Strand magazine when they began appearing there. Conan Doyle found Holmes crowding out other activities and attempted to solve the problem by killing him off in 1893.
Louise Doyle contracted tuberculosis at about this time and the family moved to Hindhead in search of health. Conan Doyle also travelled widely, both lecturing and in search of a healthy spot for his wife. In 1900 he spent some months as a volunteer in a South African hospital, in support of the British effort in the Boer War: his defence of the war's policy was probably behind his receiving a knighthood in 1902. At this time he revived Sherlock Holmes, first in a novel purporting to describe an adventure predating his death (The Hound of the Baskervilles) and then, in response to financial incentives from McClure's Magazine in the USA, bringing him back to the short story genre and explaining away his apparent death as a ruse by the master detective.
Louise Doyle died in 1906. A little over a year later Conan Doyle married again: Jean Blyth Leckie, his new wife, had been a close friend for ten years.
One of Conan Doyle's sons, Kingsley, and his brother General Innes Doyle, both died as a result of illness contracted during the First World War. These deaths and a general awareness that the war, which he had supported and for which he had propagandised, had led to millions of deaths, no doubt were a factor in Doyle's move to spiritualism in the 1920s. Evangelising for spiritualism dominated the written output of his final years, though Holmes remained as much a sceptic as ever (the final Holmes collection, The Casebook of Sherlock Holmes, appearing in 1927).
Conan Doyle died at his home in Crowborough in 1930; he was buried in the rose garden there, but later reinterred with his wife in the churchyard at Minstead in the New Forest.