Andrew was one of the two “fishers of men” personally called on by Jesus. He became one of the 12 apostles and was present for key moments in Jesus’s life, but little else is known about him — unless you read the apocryphal Acts of Andrew.
In this text from the third century, Andrew heals the blind, raises the dead, causes earthquakes, and prevents a birth caused by incest by killing the embryo inside the mother. When it came time for him to be martyred, he was set to be hanged on the same sort of cross as Jesus. Deeming himself unworthy of the comparison, Andrew begged to die on an X-shaped cross, and so it was done.
Today, Saint Andrew’s cross defines the flag of Scotland, where he is patron saint.