History
The St George’s Flag was first seen during the Middle Ages but the first recorded use was of an emblem used in the roll of account for the 1275 Welsh War.
During the Middle Ages a red cross was used on a white background as a symbol of St George. The flag may not have achieved full status of being the national flag until the sixteenth century when all the other banners were abandoned during the Reformation.
For more information about the history of the the England flag, The St Georges Cross please visit the Wikipedia entry here.