The Templars were disbanded for heresy, and for the more practical reason that kings wanted their wealth. The Inner and Middle Temple in London are now possessed by the Law Societies of those names, having at first leased the properties and then purchased them. The Templars' round church is still there and used by the lawyers although it had to be rebuilt after WWII. (Oliver Goldsmith is buried outside of it.) There was also an Outer Temple at one time but the lawyers never got their hands on it, and that area no longer goes by that name.

I don't believe that I ever heard of the Templars fighting a battle in the British Isles or Ireland. They fought the Saracens in the Holy Land, and at one point had managed to convert the mosque which still stands on Temple Mount into a church.