Matthias (Hebrew transliteration: Mattityahu; died c. 80 A.D.), according to the Acts of the Apostles, was the apostle chosen by the believers to replace Judas Iscariot following Judas’ betrayal of Jesus and suicide. His calling as an apostle is unique in that his appointment was not made personally by Jesus, who had already ascended into heaven, and, it was made before the descent of the Holy Spirit upon the early Church (https://en.wikipedia.org/wiki/Saint_Matthias).
14 May (Roman Catholic; Anglican Communion)
9 August (Eastern Orthodox)
24 February (Episcopal; Lutheran; former Roman Catholic)
All further information concerning the life and death of Matthias is vague and contradictory. According to Nicephorus, he first preached the Gospel in Judea, then in Ethiopia (that is to say, Colchis) and was crucified. The Synopsis of Dorotheus contains this tradition: Matthias in interiore AEthiopia, ubi Hyssus maris portus et Phasis fluvius est, hominibus barbaris et carnivoris praedicavit Evangelium. Mortuus est autem in Sebastopoli, ibique prope templum Solis sepultus (Matthias preached the Gospel to barbarians and cannibals in the interior of Ethiopia, at the harbour of the sea of Hyssus, at the mouth of the river Phasis. He died at Sebastopolis, and was buried there, near the Temple of the Sun). Still another tradition maintains that Matthias was stoned at Jerusalem by the Jews, and then beheaded. It is said that Saint Helena brought the relics of Saint Matthias to Rome, and that a portion of them was at Trier. Bollandus doubts if the relics that are in Rome are not rather those of the Saint Matthias who was Bishop of Jerusalem about the year 120, and whose history would seem to have been confounded with that of the Apostle. (http://catholicsaints.info/catholic-encyclopedia-saint-matthias/)