1606-1801. Union of the England St George Cross and the St Andrew Cross of Scotland. The early flag of England was the red cross of St. George only on a white field and for Scotland it was the white cross of St. Andrew on a blue field. In 1603 England and Scotland were united under King James I. In 1606 the two flags were joined together by proclamation, with the cross of St. George superimposed over the Scottish flag. Additionally, the red cross of St. George was bordered with white. The new flag was called either the King’s Colors or the Union Flag and was for use at sea in civil and military ships of both Scotland and England. In 1634 its use was largely restricted to the King's ships. The American colonies were ruled under the King's colors until the Revolutionary War.