At which battle was Dr John Watson wounded before meeting Sherlock Holmes?

Dr John Watson was wounded at the Battle of Maiwand before meeting Sherlock Holmes.

In A Study in Scarlet, Watson explains that he served as an army medical officer during the Second Anglo-Afghan War. He was attached to the Fifth Northumberland Fusiliers and was injured during the British defeat at Maiwand in 1880.

Watson’s wound and subsequent illness lead to his return to England. With limited money and no settled home, he encounters Stamford, who tells him that Holmes is seeking someone to share lodgings. This chain of events brings Watson to Baker Street and begins the central partnership of the Holmes canon.

Some readers remember Watson simply as a veteran of Afghanistan, but the specific battle is important because Doyle gives it a named historical setting. The real Battle of Maiwand took place on 27 July 1880 in present-day Afghanistan.