St. George is the patron saint of England. His emblem, a red cross on a white background, is the flag of England, and incorporated into the Union Jack, along with the flag of Scotland.
St George's emblem was adopted by Richard The Lion Heart and brought to England in the 12th century. The king's soldiers wore it on their tunics to avoid confusion in battle.By tradition, 23 April is the day for a red rose in the button hole, the national flower. However, unlike other countries, England does not celebrate it like Americans celebrate 4 July with fireworks. In fact, you are more likely to see big St Patrick's Day parades in England celebrating Ireland's National Day, more than you would see any sign of St Georges Day being celebrated. For most people in England, St George's Day is just another ordinary working day.
The Queen's actual birthday is 21st April, but the official Queen's Birthday public holiday is in June. It is not the UK's National Day.