There is no consensus on how St Andrew came to be Scotland’s patron saint, but there are a number of theories. One states that relics belonging to St Andrew were brought to Scotland in the fourth century. These relics, kept at St Andrew’s cathedral in Kinrymount, Fife, then became a major destination for medieval pilgrims.
Another possible explanation is that in the 800s, Pictish king Angus MacFergus saw a saltire cross in the sky immediately before a battle, and took Saint Andrew as his patron from then on.