What contributions did the British make to aerial combat in WWI and WWII?

I'm writing a research paper on the effect the UK had on the evolution of the airplane, and I would like to know what kind of advancements they made in terms of warfare. Ex: Did they make a specific machine gun or trigger system, did they make a particular model of aircraft that preformed well thoroughout either of the wars, did they invent anything pre, post, or during the war that was ground breaking... or air shattering I guess in this case... PLEASE INCLUDE SOURCES IF YOU CAN (if you can't, eh, whatever) Thank you for your contributions, you will be remembered.