Tradition suggests that St. Andrew (an apostle of Jesus in the Christian religion) was put to death by the Romans in Greece by being pinned to a cross of this shape.
The flag of the United Kingdom - known as the Union Flag or Union Jack - is made up from the flags of Scotland, England (the Cross of Saint George) and Ireland (the Cross of Saint Patrick).
There is a second flag which is associated with Scotland, the "Rampant Lion", or Royal Flag of Scotland. Although based on an older Scottish flag than the St. Andrew's Cross, it should, strictly speaking, now only be used by the monarch in relation to her capacity as Queen in Scotland¹. However, it is widely used as a second national flag.
The Rampant Lion flag flies over the offices of the Secretary of State for Scotland (who is the representative of the U.K. government in Scotland); that is Dover House in London and New St Andrew's House in Edinburgh.
King George V signed a Royal Warrant in 1934 allowing the use of the Rampant Lion flag as "a mark of loyalty" because of the forthcoming Jubilee celebrations. The Lord Lyon² officially now takes the view that this permission "related to decorative ebullition", that is, it is permissable to wave the flag at football matches. It is however not allowable to fly the flag without permission, on a flag-pole or from a building. The Lord Lyon once threatened the town councillors of Cumbernauld with an Act passed in 1679 which prescribed the death penalty for mis-use of the royal arms.
Och Aye Ye Ken Noo