The Oxford Dictionary of Saints by David Hugh Farmer
Simon (1st century), apostle. Called either the Canaanite or the Zealot by the Evangelists. Simon, like several other apostles, disappeares from history after Pentecost, but there are various uncertain traditions about his subsequent preaching and martyrdom. One Eastern source gives Edessa as the place of his death, but Western tradition (as represented in the Roman missal and martyrology) says that he first preached in Egypt and then joined Jude (who had been in Mesopotamia); they went together to Persia, where the suffered martydom at Sufian (or at Siani). This tradtion dates from the 6th century, but the cult goes back much further. In art Simon's usual attribute is a boat, as on East Anglian screens (with or without a book), or else a falchion, which according to the tradition reproduced by the Golden Legend, was the weapon with which the heathen priests hewed him to death. In the East the feast was kept on 1 July, the traditional date of their death, but in the West Simon & Jude are culted together on 28 October, which possibly represents the day of their translation to St. Peter's in Rome.