The historian, Bishop Eusebius of Caesarea, quotes the earlier chronicler, Hegesippus, who wrote, c. AD 180, that he had years before interviewed the grandsons of Jude the Apostle and learned that Clopas was the brother of Joseph, husband of the Virgin Mary:
Epiphanius adds that Joseph and Cleopas were brothers, sons of Jacob,
Mary of Clopas = Susanna
Hegesippus identified Clopas as a brother of Saint Joseph.
Eusebius of Caesarea, Church History, Book III, ch. 11.
Hegesippus (quoted in Eusebius Ecclesiastical History III, xi, 1; xxxii, 5-7) also wrote of Simeon son of Clopas, descended from David and a Christian, who suffered martyrdom at the age of 120 under Trajan. It appears that he was a cousin of Jesus, son of a brother of Joseph.
Second Apocalypse of James
"This is the discourse which James the Just delievered in Jerusalem and which Marem wrote down. One of the priests told it to Theudas, the father of this just man, since he was a relative of his." (New Testament Apocrypha Vol 1 pg 333 Wilhem Schneemelcher
Cleopas [Kleopas, probably a shortened form of Kleopatros]. One of the two disciples who were confronted by the risen Jesus on the road to Emmaus (Luke 24:18). The other is not named.