The Cross of St Andrew
Around the time of the 8th century, an army of Picts and Scots under King Angus found themselves surrounded by a force of Angles under their leader Athelstan. King Angus prayed earnestly for deliverance to God and the saints. That night Saint Andrew appeared to the King and promised them victory.
The next day, when battle began, the vision of the white saltire (the diagonal cross on which the Apostle Andrew had been martyred) was seen by all in the blue sky. This so encouraged the Picts and Scots and frightened their adversaries that a victory was won.
Hence, St Andrew’s Cross on a blue background became the symbol of the Scots nation.
Wooden carved detail from St Mary’s Episcopal Cathedral in Edinburgh.
(by Lawrence OP)