The Jovians and Herculians (Latin: Herculiani) were the senior palatine imperial guard

Imperial Guard

The Imperial Guard was originally a small group of elite soldiers of the French Army under the direct command of Napoleon I, but grew considerably over time. It acted as his bodyguard and tactical reserve, and he was careful of its use in battle...

 units of the Emperors of the late Roman Empire

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 and the early Byzantine Empire

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 from the 290s until the 7th century.

History

The name originated in the equation of the two co-emperors Diocletian

Diocletian

Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244  – 3 December 311), was a Roman Emperor from 284 to 305....

 and Maximian

Maximian

Maximian was Roman Emperor from 286 to 305. He was Caesar from 285 to 286, then Augustus from 286 to 305. He shared the latter title with his co-emperor and superior, Diocletian, whose political brain complemented Maximian's military brawn. Maximian established his residence at Trier but spent...

 with the Roman gods Jove

Jupiter (mythology)

In ancient Roman religion and myth, Jupiter or Jove is the king of the gods, and the god of the sky and thunder. He is the equivalent of Zeus in the Greek pantheon....

 and Hercules

Hercules

Hercules is the Roman name for Greek demigod Heracles, son of Zeus , and the mortal Alcmene...

. The old-established Praetorian Guard

Praetorian Guard

The Praetorian Guard was a force of bodyguards used by Roman Emperors. The title was already used during the Roman Republic for the guards of Roman generals, at least since the rise to prominence of the Scipio family around 275 BC...

 was based at the Castra Praetoria

Castra Praetoria

Castra Praetoria were the ancient barracks of the Praetorian Guard of Imperial Rome.-History:According to the Roman historian Suetonius, the barracks were built in 23 AD by Lucius Aelius Sejanus, the praetorian prefect serving under the emperor Tiberius, in an effort to consolidate the several...

in Rome, and had frequently proved disloyal, making and deposing emperors and even on one occasion in 193 putting the Imperial throne up for auction to the highest bidder (cf: Didius Julianus

Didius Julianus

Didius Julianus , was Roman Emperor for three months during the year 193. He ascended the throne after buying it from the Praetorian Guard, who had assassinated his predecessor Pertinax. This led to the Roman Civil War of 193–197...

). Thus Diocletian, who ruled from Nicomedia

Nicomedia

Nicomedia was an ancient city in what is now Turkey, founded in 712/11 BC as a Megarian colony and was originally known as Astacus . After being destroyed by Lysimachus, it was rebuilt by Nicomedes I of Bithynia in 264 BC under the name of Nicomedia, and has ever since been one of the most...

, promoted two faithful legions from the Illyricum

Illyria

In classical antiquity, Illyria was a region in the western part of the Balkan Peninsula inhabited by the Illyrians....

 (Legio V Iovia

Legio V Iovia

Legio V Iovia was a Roman legion levied by Diocletian in the end of the 3rd century, and was still in service at the beginning of the 5th century...

 and VI Herculia

Legio VI Herculia

Legio VI Herculia was a Roman legion levied by Diocletian in the end of the 3rd century, and was still in service at the beginning of the 5th century...

), the area he was also descended from, to be the personal protectors of the Roman Emperors. On their promotion, the two old legions were renamed Ioviani and Herculiani. The Praetorian Guard continued to exist until its abolishment by Constantine I

Constantine I

Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...

 in ca. 312, and replaced as the imperial guard by the Scholae Palatinae

Scholae Palatinae

The Scholae Palatinae , were an elite military guard unit, usually ascribed to the Roman Emperor Constantine the Great as a replacement for the equites singulares Augusti, the cavalry arm of the Praetorian Guard...

. The two legions however continued to be counted among the senior units of the army, and after its division between East and West

Western Roman Empire

The Western Roman Empire was the western half of the Roman Empire after its division by Diocletian in 285; the other half of the Roman Empire was the Eastern Roman Empire, commonly referred to today as the Byzantine Empire....

, they too were divided.

In the late 4th century document Notitia Dignitatum

Notitia Dignitatum

The Notitia Dignitatum is a unique document of the Roman imperial chanceries. One of the very few surviving documents of Roman government, it details the administrative organisation of the eastern and western empires, listing several thousand offices from the imperial court down to the provincial...

, they are listed, for the West (bearing the title seniores), as directly under the command of the magister peditum, and for the East (the iuniores, junior to their counterparts in the West), as being under the command of the magister militum

Magister militum

Magister militum was a top-level military command used in the later Roman Empire, dating from the reign of Constantine. Used alone, the term referred to the senior military officer of the Empire...

 praesentalis. In 398

398

Year 398 was a common year starting on Friday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Eutychianus...

, the Jovians and Herculians of the West were part of the small body that invaded Africa Province

Africa Province

The Roman province of Africa was established after the Romans defeated Carthage in the Third Punic War. It roughly comprised the territory of present-day northern Tunisia, and the small Mediterranean coast of modern-day western Libya along the Syrtis Minor...

 and suppressed the Gildonic revolt

Gildonic revolt

The Gildonic revolt was a rebellion in the year 398 AD led by Comes Gildo against Roman Emperor Honorius. The revolt was subdued by Flavius Stilicho, the magister militum of the Western Roman empire.-Background:...

.