I guess George was part of the Dragon Slayer order. Suffice to say that dragons won't find any refuge on this day!
Nah the Dragon slayer order is just a myth. The dragon sybolised the Roman Empire (of which George hated) and he did not actually kill such a beast but myths and legends arose from this saying he did. Mostly these were formed in medieval Europe most notably the story of the dragon taking the city water supply. They had to offer sheep and later humans as a daily sacrifice to appease the beast until eventually it was slain by George.
The St George's cross was eventually adopted as the official English flag and is our patron saint.
We should get St George's day as a public holiday in England but we dont which kinda sucks. Every other Eurpoean nation as far as I know gets a day off work on their saint's day.