Legio V Iovia

Drawing of shield of the senior Ioviani palatine legion, according to the Notitia Dignitatum. Legio V Iovia was a Roman legion, recruited by Diocletian at the end of the third century, and was still in service at the beginning of the fifth century. Its cognomen refers to the god Jupiter, of whom Diocletian (also known as Iovianus, "the man like Jupiter") was devout and with whom he identified. The V Iovia was quartered, together with the sister legion VI Herculia, in Pannonia Secunda, a new province created with the segregation of the old province of Pannonia Superior. The Legion received the ordinal "Quinta" because in Panonia there were already four legions. The purpose of the legion, having its permanent camp at Bononia and an advanced castellum at Onagrinum, was to protect the imperial residence of Diocletian at Sirmium.

The Notitia Dignitatum still places the legion in Illyricum at the beginning of the fifth century. It is possible that some men of this legion and VI Herculia formed the Jovianos and Herculianos, the new imperial guard of Diocleciano. If this identification is correct, men of the V Iovia had the appellation of martiobarbuli, since they were experts in throwing small darts, carried in five in the interior of their shields.

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