From “Sermon for St. Matthias,” The Golden Legend (ca. 1260)
When the time came between the Ascension and Whitsuntide, St Peter beheld that the number of the apostles was diminished. He arose up in the middle of the disciples and said: “Fair brethren, you know how our Lord Jesus Christ had chosen twelve men to bear witness of his resurrection, and Judas was gone the evil way. It behooves us to accomplish the number twelve of such as have been with him.”
And they chose two of them that were there, that one was named Joseph surnamed Justus, and that other was Matthias. And then they made their prayers and said: “Lord God, who knows the hearts of all, show to us whom we shall choose of these two here.” And after, they cast lots, and the lot fell on Matthias, who was then numbered with the other eleven, and then were they twelve again.
St. Denis saith that the lot was a shining ray which came and shone upon Matthias. And he began to preach, and had his preaching about Jerusalem, and was very virtuous, and he did many miracles… Matthias was firm in the love of God, and clean of his body, and wise in speaking of all the questions of scripture, and when he preached the word of God many believed in Jesus Christ by his preaching.
The Jews took him and brought him to justice and had gotten two false witnesses against him to accuse him. They cast on him first stones, and he prayed that the stones might be buried that the false witnesses had cast upon him, for to bear witness against them that stoned him, and finally he was slain with an axe after the manner of the Romans. And he held up his hands and commended his spirit to God. And after it is said that his body was brought to Rome, and from Rome it was translated to Treves. Another legend saith that his body lies at Rome, and was buried under a stone of porphyry in the church of St. Mary Major.
James of Voraigne (1228-1298) was an Italian historian and Archbishop of Genoa. A member of the Dominican Order, he was a celebrated preacher, but is best known for The Golden Legend, a collection of the legends of the greater saints of the medieval liturgical calendar, a work that became immensely popular, the most printed work in the first five decades following the invention of movable type.