What do the crosses on the union jack mean?

Question

What do the crosses on the union jack mean?

Answer 1

The Union Jack is based on a combination of three other flags, that of Scotland (a white saltire or Saint Andrew's Cross on a blue background), Ireland (the St Patrick's Flag of a red saltire on a white background), and Genoa (a red St George's Cross on a white background).

England adopted the Genoa flag in 1190 to benefit from Genoese protection for their ships entering the Mediterranean.  In 1606 the flag was adapted to include the Scottish flag.  Finally, in 1801, the United Kingdom was formed and the St Patrick's Flag added in.

http://en.wikipedia.org/wiki/Union_Flag

Answer 2

It is called the Union Flag because it symbolises the administrative union of the countries of the United Kingdom. It is made up up of the individual Flags of three of the Kingdom's countries all united under one Sovereign - the countries of 'England, of 'Scotland' and of 'Northern Ireland'

England is represented by the flag of St. George - Red cross on a white background

Scotland is represented by the flag of St. Andrew - White diagonal cross on a blue field

Ireland is represented by the cross of St. Patrick - Red diagonal cross on a white field