re: How were the British so successful militarily?

As much as I hate to admit it, there's only one service that has made us a superpower, the squids. When you can move goods and forces across the ocean and the other guy can't, you win.

The Brits never had to worry about being conquered from the days of Elizabeth I til now because of the Royal Navy. They could bottle up their foes economically, while never suffering from economic blockade themselves. And, in the Victorian era, their army was facing unsophisticated savages, for the most part.