 The term Union Jack possibly dates from Queen Anne's time (reigned )  It may come from the 'jack-et' of the English of Scottish soldiers;  or from the name of James I who originated the first union in 1603

 The flag consists of three heraldic crossed. The cross of St George, patron saint of England since the 1270's, is a red cross on a white ground.

 The cross saltire of St Andres, patron saint of Scotland, is a diagonal white cross on a blue ground.

After James I succeeded to the throne, it was combined with the cross of St Andrew in On 12 April 1606 a proclamation was issued: "All our subjects in this our isle and kingdom of Great Britain and the members thereof, shall bear in their main top the red cross commonly called St George's Cross and the white cross commonly called St. Andrew's Cross joined together according to a form made by our heralds and sent to our Admiral to be published to our said subjects."

 The second Act of Union 1800

 The legislative union of Great Britain and Ireland was completed on January 1st CChanging the country’s name to “ United Kingdom of Great Britain and Ireland”