Simon, whom St Matthew calls the Cananean to distinguish him from St. Peter who bore the same name, was born at Cana in Galilee. St. Luke calls him Zelotes, because he had probably belonged to the Jewish parly, thus called for its zeal in defending the faith.
Jude, surnamed Thaddeus or Lebbe (the courageous) was by Cleophas his father and Mary his mother, a nephew to St. Joseph and the Blessed Virgin and cousin to Jesus. St. James, the Less, first bishop of Jerusalem and the first apostle martyred, and Simeon who succeeded him in this see, were his brothers.
These apostles of Christ heard from the lips of the Master at the Last Supper the words of the Gospel: I am the vine, you are the branches. Every branch which bears fruit, My Father shall prune in order that it should bear more. After having preached the Gospel at the price of great sufferings, the first in Egypt, the second in Mesopotamia, they were both martyred in Persia. (Introit, Gradual, Communion). Wherefore their feasts are celebrated on the same day in the same office and their names are mentioned jointly in the Canon of the Mass.
Intret in conspectu tuo, Domine, gemitus compeditorum: redde vicinis nostris septuplum in sinu eorum: vindica sanguinem sanctorum tuorum, qui effusus est. * Deus, venerunt gentes in hereditatem tuam, polluerunt templum sanctum tuum: posuerunt Jerusalem in pomorum custodiam.
Let the sighing of the prisoners come in before Thee, O Lord; render to our neighbours sevenfold in their bosom; revenge the blood of Thy saints which hath been shed. * O God, the heathen are come into Thine inheritance: they have defiled Thy holy temple; they have made Jerusalem as a place to keep fruit.
(Psalm 78:11,12,10 from the Introit of Mass)
Concéde, quaesumus, omnípotens Deus: ut, sicut Apostolórum tuórum Simonis et Judae gloriósa natalítia praevénimus; sic ad tua benefícia promerénda, majestátem tuam pro nobis ipsi praevéniant.
Grant, we beseech Thee, almighty God, that even as we anticipate the glorious festival of Thy apostles Simon and Jude, so they, in imploring from Thy majesty thy blessings for us, may anticipate our prayers.