St. Andrew was the patron saint of Scotland and also the patron saint of Greece, Russia, and Romania. He was the brother of the first Catholic Pope, St. Peter, and one of the first apostles of Jesus. [1] Andrew is said to have been killed in Patras, Greece. He requested the Roman authorities who sentenced him to death not to allow him to be crucified in the same position as Jesus. His request was approved, and he was ultimately executed on an X-shaped cross (St. Andrew's Cross or X-shaped Cross), which later became his symbol.

The national flag of Scotland is the blue and white St. Andrew's Cross flag (i.e. the flag on a colored background) × The cross shaped pattern is derived from St. Andrew, a Scottish saint who was crucified on an X-shaped cross.
The connection between St. Andrew and Scotland originated from two legends. One is that it is said that the relics of the saint were brought by St. Regulus from Patras to Kinrymont in Fife in the 4th century, and his ship was later sunk on the east coast. Afterwards, Kinrymont's church became St. Andrew's Cathedral and gradually developed into an important center for medieval pilgrimage. Another version is that in the 9th century, due to the appearance of an X-shaped cross in the sky before the victory of Athelstaneford in the war, King Angus mac Fergus of Pickett regarded St. Andrew as the patron saint.

According to relevant data, St. Andrew became the patron saint of Scotland around 1000 AD. In 1286, the front of the Scottish Guard seal bears the design of St. Andrew nailed to an X-shaped cross, as well as the Latin inscription Andrea Scotis Dux Eesto Compatriotis - 'St. Andrew is the leader of all Scottish compatriots'. In 1390, during the reign of Robert III, St. Andrew was first inscribed on a five shilling coin as a National symbol.
Saint Andrew's Day is November 30 every year, but it is not a public holiday in Scotland.

According to historical records, a battle occurred near Athelstaneford in 832 AD, which prompted people to start using the St. Andrew's Cross as the national flag of Scotland. Under the leadership of Angus mac Fergus, the king of Alba, Pickett and the Scottish coalition invaded the Northumbrian territory of Lothian. In this battle, Angus' army was surrounded by a larger number of Anglo and Saxon armies and faced the risk of failure. However, the Chinese king asked the monks to pray for divine will. Not long after, when Angus saw a scene like the Cross of St. Andrew in the azure sky, he believed it was God's will for him. So the king immediately swore that if St. Andrew helped him win, then from then on St. Andrew would become the patron saint of Scotland, and his cross would become the flag of Scotland. Angus truly achieved victory, and the St. Andrew's Cross became the national flag of Scotland as it should have been.
Whether it is divine or not, the St. Andrew's Cross flag was widely used in the 14th century, but it was not fixed on using blue as the background color. In fact, it was not until the 16th century that the St. Andrew's Cross flag with a blue background and a white cross was finally formed. Throughout the 17th century, especially in the army and navy, the saltire flag has always been the symbol of the country, and it was added to the flag of the United Kingdom when Britain was reunified.
Nevertheless, in 1707, Congress decided to abandon the use of the St. Andrew's Cross, and it was not until the latter half of the 20th century that it was re used. Now, it has become the legal national flag of Flag of Scotland again. All Scottish teams use it in international competitions, and most of the flagpoles in front of public buildings also fly the flag, sometimes alone, sometimes with the United Kingdom flag. Due to its simple design, many private and public groups also use it as an element of corporate identity.

In 2003, Scottish officials stipulated the color of the flagpole and clarified the specific tone of St. Andrew's Cross Blue. Since then, the blue color requirement has been based on the Pantone 300 in the international color standard system, with the white St. Andrew's Cross reflected on it. Nevertheless, this standard is not a mandatory requirement, and the St. Andrew's Cross flag can continue to have a variety of colors as the base color.

In 1997, a memorial center for the St. Andrew's Cross was opened in a restored small building next to the Athelstaneford Church. Here, people can learn more about the St. Andrew's Cross and even learn its origin from a short audio-visual clip. This commemorative center is open to visitors for free from 10 am to 5 pm every day from April to September. The Memorial Hall has been encouraging people to visit since its opening in 1965. The St. Andrew's Cross flag will always flutter in the wind above the Memorial Hall, and even at night, it will continue to flutter in the light.