The Union Flag, combining the flags of England and Scotland, is adopted for the first time on April 12, 1606, by Royal decree from King James I & VI, combining the English, red St George's Cross and the Scottish white saltire, St Andrew's Cross on a blue field.
Ordered by King James I & VI, the flag was established for use by the Navies royal vessels from both kingdoms to prevent confusion between English and Scottish ships.Its adoption in 1606, was a crucial step in formalizing the union between England and Scotland long before the political union in 1707.This flag became the national flag of Great Britain in 1707. it was modified in 1801 to include the cross of St. Patrick (Ireland) to create the modern Union Jack.