Eric IX of Sweden, (Swedish: Erik Jedvardsson; Erik den helige), also called Eric the Lawgiver, Erik the Saint, Eric the Holy, and, in Sweden, Sankt Erik, meaning Saint Eric, was a Swedish king c. 1156-60. No historical records of Eric have survived, and all information about him is based on later legends that were aimed at having him established as a saint. The Roman Martyrology of the Roman Catholic Church names him as a saint memorialized on 18 May.
Eric was responsible for codifying the laws of his kingdom, which became known as King Eric's Law (or the Code of Uppland). Additionally, he established a monastic chapter in Old Uppsala, which had come from the Danish abbey of Odense. He also established an unpopular system of tithes to support the Church similar to elsewhere in Europe.
Swedish nobles allied with the rival House of Sverker dynasty accosted Eric near Uppsala at Östra Aros as he was leaving church after hearing mass on Ascension Day in May 1160 or 1161. He was pulled off his horse onto the ground by the swarming rebels, who taunted and stabbed him, then beheaded him. One version names his assassin as Emund Ulvbane, hired by the Sverker dynasty.
Referring to Erik Jedvardsson as King Eric IX is a later invention, counting backwards from Eric XIV (1560-8). He and his brother Charles IX (1604-11) adopted numerals according to a fictitious history of Sweden. The number of Swedish monarchs named Eric before Eric XIV (at least seven) is unknown, going back into prehistory, and none of them used numerals. It would be speculative to try to affix a mathematically accurate one to this king.