Saint Andrew's Cross

St. Andrew's Cross
It is believed that the apostle Andrew was crucified on a saltire (X-shaped) cross; hence the name St. Andrew's Cross. He is supposed to have told his executioners that he was not worthy to be crucified on the same cross style as Jesus, and persuaded them to alter the shape. If this is true, it's a remarkable example of stoicism displayed by a man, no doubt beaten and starved, yet retaining the mental energy to plead such a thing with his brutal executioners. Detailed records of his crucifixion only date back to the Middle Ages, and these records are influenced be the imagination of the medieval artists. But even if the origin is a myth, the cross shape reminds Christians that they should exercise humility.
Before Peter was crucified, he too requested that a cross different to Christ's Latin Cross be used. Therefore we have another cross that Christians associate with humility, which is the upside-down Latin Cross, known as St. Peter's Cross.
Instead of simply saying that something is 'X-shaped', the term 'St. Andrew's Cross' is used for several items that have absolutely nothing to do with St. Andrew or even religion. For example, there is argiope mangal - a tiny, brightly striped spider found in the mangroves of Singapore. This is commonly known as 'St. Andrew's Spider' because it holds its eight legs in pairs, forming an X shape. Then there's the hypericum hypericoides, a small shrub of the St. John's-wort family. Its flowers form a cross with their four yellow petals.
The saltire is seen on several national flags. For example the white cross on a blue background as the flag of Scotland, and a red cross on a white background as St. Patrick's cross of the Irish. Both of these crosses were superimposed on England's red cross on a white background, St. George's Cross, to give the United Kingdom's Union Flag ('Union Jack').
All these crosses represent the Christian religion of the kings at the time the flags were made. The Union Flag also forms part of the flags of many other countries, including: Anguilla, Australia, Bermuda, British Virgin Islands, Cayman Islands, Falkland Islands, Fiji, Montserrat, New Zealand, St Helena, Turks & Caicos, and Tuvalu.
Other national flags have an 'X' cross, but these have no Christian basis. The flag of Burundi for example, where even though the country is nominally 'Christian', the white cross is not used as a religious symbol. It is a symbol of peace - the goal of everyone after years of ethnic violence between Hutu and Tutsi factions. The flag of Grenada just happens to have a cross made by the four triangles of wisdom, warmth, vegetation and agriculture. The yellow/gold cross on the Jamaican flag signifies sunshine, as with the Macedonian flag.


St. Andrew's crossScotland St. Patrick's crossIreland St. George's crossEngland
Union flag

There is a variation of St. Andrew's cross on the flag of the Vatican. Since the 14th century, two crossed keys have been the official insignia of the Holy See. These keys are the symbols of St. Peter (popes are the direct descendants of St. Peter's office). The keys were given to Peter by Christ to open the doors to paradise, just as the cross does for all Christians.

The Vatican's flag

Some might say the Southern Cross on the American Confederate flag is the Christian symbol from the St. Andrew's cross, since many Southerners have Scottish ancestors. Others may say the flag is racist.
...which all goes to show that the real meaning of a flag, or a cross, is whatever we want it to be.