We will probably incur the wrath of English people the world over for saying this, but nearly all the stories you have heard about St. George aren't true. That doesn't, however, mean that he isn't a meaningful namesake for a church such as ours.
Nothing of George’s life or deeds can be established, but tradition holds that he was a Roman soldier and was tortured and decapitated under Diocletian’s persecution of Christians in 303. His remains were taken to Lydda (now Lod, Israel), the homeland of his mother, and were later transferred to the church that was built in his name there. Various relics reportedly are housed in both Western and Eastern churches worldwide. St. George’s Chapel of Windsor Castle, for example, is said to have once held two fingers, part of the heart, and part of the skull of the saint.