Sherlock has been called the most famous fictional character of the last two centuries, along with Dracula and James Bond. This reference is from Charles McDermid in a Back Story for the NY Times to which I have been unable to link (it is part of an emailed Newsletter). Excellent Britannica biography here. His website here. Wikipedia entry, also good.
Doyle is often referred to as "Conan Doyle". But he was baptized at St Mary's Cathedral, Edinburgh–with "Arthur Ignatius Conan" as his given names and "Doyle" as his surname. Ignatius of Loyola is the anglicized name of the founder of the Jesuit Order. Doyle's second wife was known as Jean Conan Doyle rather than Jean Doyle.
Doyle's parents were both Irish Catholic, though his father was born in England. His mother was the inspiration of his life and she was a great story-teller. Alas, his father, although from a family with some fame in the art world, suffered from alcoholism and in 1864 the family dispersed to different homes in Edinburgh with some respite in 1867 as the family came together again in an inadequate tenement flat. Doyle's father suffered from mental illness later in his life and died in 1893, in Dumfries. Fortunately Doyle's talent was spotted by wealthy uncles and a lodger. He was sent away to school at nine years of age to a school that fed to the Jesuit Stonyhurst College. From there in 1875-76, he was educated at another Jesuit school, Stella Matutina in Feldkirch, Austria. He later rejected the Catholic faith and became an agnostic and mystic.
In 1876-1881, Doyle studied medicine at the University of Edinburgh Medical School, including periods working in different locations in England including Warwickshire and Shropshire. During that time, he studied practical botany and started writing short stories. His earliest extant fiction was "The Haunted Grange of Goresthorpe", unsuccessfully submitted to Blackwood's Magazine.
His first published piece, "The Mystery of Sasassa Valley", set in South Africa, was printed in Chambers's Edinburgh Journal in 1879. The same year, he published his first academic article, on a poison.
After his graduation from Edinburgh University with a Bachelor of Medicine degree in 1881, he was ship's surgeon on the SS Mayumba during a voyage to the West African coast. He completed his advanced Doctor of Medicine degree on tabes dorsalis in 1885. He set up a medical practice in Southsea in June 1882, with less than £10 (about $1,500 today) in his pocket. It was not successful, giving Doyle ample time to write fiction. He also wrote several articles denouncing anti-vaccinators. In early 1891, Doyle attempted the study of ophthalmology in Vienna, but his German wasn't up to all the medical terms and he quit.
Returned to London, Doyle opened a small office and consulting room at what is now 2 Upper Wimpole Street. He never had luck with finding patients, giving him the time to develop a story featuring a man named Sherlock Holmes and his sidekick Dr. Watson. The novel, A Study in Scarlet, initially had no luck.
Then, to Doyle's initial delight, the book was accepted by Ward Lock & Co. It was 20 November 1886, and the wonderful publisher gave Doyle £25 (about $4,000 today) for all rights. The piece appeared a year later in the Beeton's Christmas Annual and received good reviews in Edinburgh. Holmes said the character was partly based on a former university teacher. Robert Louis Stevenson, also born in Edinburgh, was able, reading the story in Samoa, to recognize that a medical school professor was the basis of the Sherlock character.
A sequel was commissioned, and The Sign of the Four appeared in Lippincott's Magazine in February 1890, under agreement with the Ward Lock company. By now, Doyle started to feel exploited by his wonderful publisher and left Ward Lock, sending his stories to the Strand Magazine.
Tired of his creation, Doyle tried to discourage his new publisher from demanding more work and raised his fee for new work to a level intended to send them away. Alas, the new magazine promptly accepted. He therefore became one of the best-paid authors of his era.
In December 1893, he went so far as to finish off both Holmes and his arch-enemy Professor Moriarty, sending them both over the Reichenbach Falls to their deaths in "The Final Problem". The public was outraged. They cancelled 20,000 subscriptions to the Strand Magazine.
He was after a few years prevailed upon to revive Holmes in 1901 in the novel The Hound of the Baskervilles. In 1903, Doyle came back to a Holmes short story after a ten-year lapse, with "The Adventure of the Empty House". Doyle explains that Moriarty had indeed fallen to his death, but Holmes wanted privacy and only faked his death.
Doyle eventually accumulated 56 short stories—the last published in 1927—and four novels about Holmes. Doyle was knighted for a report he wrote on the Boer War. He showed a deep interest in the supernatural and helped popularize a famous garden fairies hoax of the early 20th century. He died of a heart attack in 1930.