The flag of the United Kingdom



is made up of the flag of St Andrew, the Patron Saint of Scotland (diagonal white cross on a blue background), St George, Patron Saint of England (red cross on white background) and St Patrick, Patron Saint of Ireland (diagonal red cross on white background).

As far the significance of the Scottish flag goes, legend has it that in 832 AD, an army of Scots was facing a Northumbrian army. The Scottish king prayed to St Andrew for help, and saw the saltire of St Andrew (the saint had been martyred on a diagonal cross) in the heavens against a clear blue sky. On seeing the cross in the sky, he swore that if the Scots beat the English in the battle that was about to be joined, then St Andrew would forever be the patron saint of Scotland. They did win the battle, and from that day on the saltire has been the national flag of Scotland.



I googled it, I didn't remember all the details of the story from my dim and distant childhood. I could google the others as well, but I'll leave room for other people.