HISTORY OF THE UNION JACK
The History of the Union of England Scotland
and Ireland flags
St George's Cross plus St Andrew's Cross made up the
first Union flag in 1606
The issue of whether it is acceptable to use the term "Union Jack" is one that causes considerable controversy. Although it is often asserted that "Union Jack" should only be used for the flag when it is flown as a jack (a small flag flown at the bow of a ship).
It is not universally accepted that the "Jack" of "Union Jack" is a reference to such a jack flag; other explanations have been put forward. The term possibly dates from the early 1700s, but its origin is uncertain. The word Jack may have come from the name of James VI, King of Scots who inherited the English crown, causing the flag to be designed, that is Jac from Jacobus, Latin for James.
The size and power of the Royal Navy internationally at the time could also explain why the flag was nicknamed the "Union Jack"; considering the navy was so widely utilized and renowned by the United Kingdom and Commonwealth countries.
It is possible that the term "Jack" did occur due to its regular usage on all British ships using the "Jack Staff" (a flag pole attached to a ship on the bow), indeed the term 'Jack' is used for sailors, hence the phrase 'Jack of all trades'.
Even if the term "Union Jack" does derive from the jack flag (as perhaps seems most likely), after three centuries, it is now sanctioned by usage, has appeared in official usage, and remains the popular term.
The image shown below highlights the construction of the eventual "Union Jack" .
After the flag of Ireland was merged the final image
became known as the Union Jack