To distinguish him from Simon Peter, in both the gospels and the acts he is called Simon Zealot. He was known as the Patriot or the Zealot as he was probably attached to a group of terrorists or freedom fighters before he met Jesus (Luke 6: 12-16)
He is one of the most mysterious of Jesus’ apostles and some suggest that he could perhaps be the cousin of Jesus or a son of Joseph from a previous marriage.
After Jesus’ death, traditions about him vary. He is reported to have gone go to Egypt to spread the Good News and then joined Jude in Persia and Armenia, where they were both martyred in 65AD
In art, Simon is often depicted with a saw, because traditionally he was martyred by being sawn in half.