The Union Flag, known as the Union Jack is the National Flag of the United Kingdom.The British Flag, and it symbolizes the administrative union of the countries of the Union Kingdom. Until the early 17th century and since the 13th century the English Flag and jack, were used by both the merchant and navy ships. This had been white with red cross of St George. The Scottish flag was blue with the white cross of St Andrew. Then on the 12th April 1606 King James I of England and Scotland issued a Proclamation that these flags should be joined together/ This was the start of the Union Jack Flag. It is probably the best known flag in the world.
Until 1634 the flag was used on both merchant and navy ships, after this it was restricted to the Kings own ships. English merchant ships reverted to the St George Cross and the Scottish Ship to the St Andrews Cross. When the United Kingdom of Great Britain and Ireland came into existance on 1st January 1801, a red Saltire called the cross of St Patrick was chosen to represent Ireland. It Originated in the coat of arms of the Ango-Irish family of Fritzgerald.