[1] 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 came before the descent of the Holy Spirit upon the early Church.

Even his name is variable: the Syriac version of Eusebius calls him throughout not Matthias but "Tolmai", not to be confused with Bartholomew (which means Son of Tolmai), who was one of the twelve original Apostles; Clement of Alexandria refers once to Zacchaeus in a way which could be read as suggesting that some identified him with Matthias;[4] the Clementine Recognitions identify him with Barnabas; Adolf Bernhard Christoph Hilgenfeld thinks he is the same as Nathanael in the Gospel of John.

The tradition of the Greeks says that St. Matthias spread Christianity around Cappadocia and on the coasts of the Caspian Sea, residing chiefly near the port Issus.

[a][6] A marker placed in the ruins of the Roman fortress at Gonio (Apsaros) in the modern Georgian region of Adjara claims that Matthias is buried at that site.

The Synopsis of Dorotheus contains this tradition: "Matthias preached the Gospel to barbarians and meat-eaters in the interior of Ethiopia, where the sea harbor of Hyssus is, at the mouth of the river Phasis.

According to the newer Common Worship liturgy, Matthias is remembered in the Church of England with a Festival on 14 May,[11] although he may be celebrated on 24 February, if desired.