Three entries with the name Tiberius.
Tiberius
According to Jacob van Maerlant, a Roman Emperor and father of Vespasian, who freed Joseph of Arimathea from a prison in Jerusalem. The Vulgate stories name him Titus.
An Emperor Tiberius I ruled Rome from AD 14 to 37, but six other emperors ruled between Tiberius’s reign and Vespasian’s.
Tiberius
The surname of Lucius the Roman in some chronicles, given as his sole name in Hughes’ The Misfortunes of Arthur.
Source
The Misfortunes of Arthur | Thomas Hughes, 1587
Tiberius
Tiberie, Tyberius Cesar
An Emperor of Rome during Arthur’s reign. Claudas asked him for support in his war against Arthur.
Source
Vulgate Lancelot | 1215-1230