Aristobulus of Britannia is a Christian saint named by Hippolytus of Rome (170–235) and Dorotheus of Gaza (505–565) as one of the Seventy Disciples mentioned in Luke 10:1–24 and as the first bishop in Roman Britain.

[5] : 118–121 Orthodox tradition says Aristobulus was the brother of the Apostle Barnabas, of Jewish Cypriot origin.

[6] He was one of the assistants of Saint Andrew,[7] along with Urban of Macedonia, Stachys, Ampliatus, Apelles of Heraklion and Narcissus of Athens (all of these names are mentioned together by St. Paul in Romans 16:8–11, which cannot be casual).

[8] The Benedictine monk Serenus de Cressy (1605–1674) maintained that Aristobulus was ordained by St. Paul and died at Glastonbury Abbey in 99; but Michael Alford (author of Fides Regia Britannica Sive Annales Ecclesiae Britannicae) says that Aristobulus was the husband of "Mary" Salome, which makes this date appear too late.

[11][12] This is in accord with the date given by Gildas (c. 500–570 AD) that the "Light of Christ" shone in Britain in the last year of Emperor Tiberius.

For this and other reasons, Smith also considers the account of Joseph of Arimathea a "superstitious fable of comparatively modern invention".

[15] John Williams identifies Aristobulus with Arwystli Hen, a "man of Italy", and one of four missionaries believed to have brought Christianity to the British Isles.

He participated with his forces in the Roman–Parthian War of 58–63, where he received a small portion of Armenia in exchange,[22] an area he continued to rule until 72 when Vespasian reduced the regional autonomy of some of the provinces.