The United Kingdom of Great Britain and Northern Ireland flag is really made up of the three flags of England, Scotland and formerly the totality of Ireland up until 1921.
The crosses of each country’s Patron Saint combined form the U.K flag.
England: Cross of St George – Red Cross
Scotland: Cross of St Andrew – White Saltaire
This is the scottish flag
N. Ireland: Cross of St Patrick – Red Saltaire
Right Way Of Displaying The Union Jack
Some historians believe that the Union Flag is called 'Jack' because it´s named after James I (Jacobus in Latin ) since he introduced the flag after acceding to the throne and was the first monarch to be called King of Great Britain.