United Kingdom Flag:
The United Kingdom flag was officially adopted on January 1, 1801, and it's arguably the world's best known flag.
In short, this striking flag is actually a composite of England's St. George's Cross (the centered red cross bordered in white), St. Andrew's Cross of Scotland (the diagonal white cross on the blue field), and the Patron Saint of Ireland (diagonal x-shaped red saltire).
Larger United Kingdom flag 
United Kingdom Coat of Arms:
The United Kingdom Royal Coat of Arms consists of a shield divided into four quadrants. One of the quadrants contain the guardant lions of England. Two of the quadrants contain the rampant lion of Scotland. The final quadrant contains a harp which represents Northern Ireland.
Supporting the shield are a crowned lion and a unicorn. The crowned lion represents England and the unicorn represents Scotland. The crowned lion also crowns the Coat of Arms.
The Coat of Arms also contains Latin phrases meaning "God and my right" and "Shamed be he who thinks ill of it".
These arms are used by the Queen or King in their official capacity as monarch, and are officially known as the Arms of Dominion.
