Ulpia is Trajan's own gens, while the cognomen "Victrix" means "victorious," and it was awarded after their valiant behaviour in the Dacian Wars.
In 122 they were moved to Colonia Ulpia Traiana (modern Xanten[3][4]) in Germania Inferior, where they remained for the following centuries.
In the 2nd century and the beginning of the 3rd century, units of the XXX Ulpia Victrix were allocated in Parthia, as well as Gaul, Mauretania and other Roman provinces, due to the peaceful situation in Germania Inferior.
[5] In the civil war of 193, XXX Ulpia Victrix supported Septimius Severus, who granted them the title of Pia Fidelis ("faithful and loyal").
It supported the Gallic Empire of Postumus (260–274) and suffered great losses when Aurelian overthrew Tetricus I in a bloody battle at the Catalaunian Fields in 274.