Simon is usually called “the Canaanite” and “the Zealot,” suggesting that he belonged to the Jewish party of the “Zealous of the Law.” He usually appears eleventh in the list of the apostles. Nothing is known of him except that he was born at Cana in Galilee.
Jude or Thaddeus has a short epistle in the New Testament ascribed to him, and is popularly invoked as the patron of hopeless causes. He was the apostle who asked the Lord at the Last Supper why he had manifested himself only to his disciples and not to the whole world (Jn 14:22).
Tradition says that after Pentecost they evangelised, Simon in Egypt, Jude in Mesopotamia, and then together in Persia, where they were martyred. Their names appear in the Roman Canon. – CTS New Daily Roman Missal 2012, p 3095; Christian Prayer 1990, p 1262