Here's what we know about his military service:
* He served as an army doctor in the 2nd Afghan War (1878-1880). This is mentioned several times in the stories, and his experiences there are referenced as shaping his personality and providing him with useful skills.
* He was wounded in the war, likely by a bullet, leading to his limp. This is described in "A Scandal in Bohemia," and the limp is a recurring detail in his portrayal.
While Watson's military past is a significant part of his character, he doesn't directly engage in any wars within the original canon. He does, however, demonstrate his combat skills in stories like "The Adventure of the Speckled Band" and "The Adventure of the Dancing Men" where he tackles danger with courage and resourcefulness.
Now, if you're thinking about different adaptations of Sherlock Holmes:
* In some adaptations, Watson might be depicted as having fought in other wars. This might be done to create a more exciting or historically relevant narrative.
* In modern adaptations, Watson's military background is often updated. He might be a veteran of a recent conflict, like the Iraq War, to reflect modern-day society.
It's always worth considering the specific version of Sherlock Holmes you're looking at to see how Watson's military background is portrayed.