The History of the Saint Andrew’s Cross Flag: The early flag of Scotland, known as a Saltire, or diagonal cross, is supposedly representative of the martyrdom of St. Andrew. The combination of this and the cross of St. George create the British Union Jack. The Scots were not happy that part of their cross was covered by the St. George cross. The St. Andrew’s cross continued to fly on the foremast of Scottish ships after the establishment of the British Union.