I've never quite understood how such a small island, with a relatively small population became such a potent military force, both in the Medieval period and then during colonisation. I don't mind how in depth anyone wants to go, since I have time today, and I'll be reading every comment. :)
See the answer by u/starwarsnerd222 to https://www.reddit.com/r/AskHistorians/comments/me018f/how_did_the_british_empire_rise/?utm_medium=android_app&utm_source=share
And search for other answers in the subreddit.