Establishment Augustus was the first to advance the empire's south-eastern European border from Macedonia to the line of the Danube to increase strategic depth between the border and Italy and also to provide a major river supply route between the Roman armies in the region. The lower Danube was given priority and
Marcus Licinius Crassus, proconsul of Macedonia from 29 BC, drove the Bastarnae back toward the Danube.
Legion IV Scythica was initially stationed in Moesia (probably at
Viminacium) to counter threats from neighbouring Thrace and aggressive peoples north of the Danube. But as a result of the Dacians constant looting that occurred whenever the Danube froze, Augustus decided to send against them some of his proven generals such as
Sextus Aelius Catus and
Gnaeus Cornelius Lentulus Augur (sometime between 1-11 AD). Lentulus pushed them back across the Danube and placed numerous garrisons on the right bank of the river to defend against possible and future incursions. These became the Moesian Limes. At this stage forts on the frontier consisted of earth walls with wooden palisades. Moesia became a separate province in 6 AD. Roman military excursions across the Danube continued over 100 km to the north of the Danube delta. The
Dacians raided south of the Danube in 68/69 and at the end of 85 or the beginning of 86 AD the
Dacian king Duras attacked Moesia and caught the Romans by surprise since the governor,
Oppius Sabinus, and his forces were annihilated. Just before
Domitian's Dacian War that followed, Domitian replaced the wood and earth walls of Danubian forts by stone walls in 87 AD (e.g. at
Taliata). Accompanied by
Cornelius Fuscus, Prefect of the
Praetorian Guard, he personally arrived in Moesia with legions
Legio IV Flavia Felix from Dalmatia,
Legio I Adiutrix and
Legio II Adiutrix and eventually cleared the invaders from the province.
Expansion beyond In the winter of 98/99 AD Trajan arrived on the Danube, quartered at the
Diana Fort near
Kladovo, and started Dacian war preparations on the
Iron Gates gorges. He extended the road in the gorge for 30 miles, as he stated on the well-known inscription of 100 AD. In 101 he also cut a canal nearby, as he also recorded on a marble plaque near
Diana Fort which reads: “because of the dangerous cataracts he diverted the river and made the whole Danube navigable”: (ob periculum cataractarum, derivato flumine, tutam Danuvii navigationem facit). Trajan restored stone defences in the area and rebuilt all earthworks in stone. Just below the
Pontes fort a large port and massive
horrea were built. Between the first and second Dacian wars, from 103 to 105, the imperial architect
Apollodorus of Damascus constructed
Trajan's Bridge, one of the greatest achievements in Roman architecture. Full military occupation of the plain between the Carpathian foothills and the Danube may already have occurred by the end of
Trajan’s
First Dacian War (101/102). The majority of forts here, however, were established after the final conquest of the Dacian kingdom in 106 AD. However, the Romans did remove the garrisons of the Danube Limes because of the need to preserve the control of transport and trade on the danube and because troops there were a kind of strategic reserve for other fronts if needed. The abandonment of
Moldova and the creation of the
Limes Transalutanus can both be tentatively dated to the reign of
Hadrian. After a long period of peace
Septimius Severus reconstructed the Moesia Superior defences and under
Caracalla more reconstruction was done as can be seen at Pontes where, as with many other Iron Gates forts, the original layout was supplemented with the gates and towers. A new fort was built on an island at the Porečka river.
Retreat to the Danube The Roman abandonment of Dacia probably occurred during the reign of
Gallienus (260-68), before the traditional date of around 275 when
Aurelian established the new province of Dacia south of the Danube. In the Late Roman period, the extent of control and military occupation over territory north of the Danube remains controversial. One Roman fort (
Pietroasa de Jos), well beyond the Danubian Limes and near
Moldavia, seems to have been occupied in the 4th century AD, as were bridge-head forts (
Sucidava,
Barboşi, and the unlocated Constantiniana Daphne) along the left bank of the river. The "
Brazda lui Novac de Nord" (or "Constantine Wall") has been shown by recent excavations to date from emperor
Constantine around 330 AD, at the same time as the "
Devil's Dykes" (or "Limes Sarmatiae"), a series of defensive earthen ramparts-and-ditches built by the Romans between Romania and the
Pannonian plains. Similarly, although considered 1st century and believed to predate the Limes Transalutanus, the function and origins of a shorter section of bank and ditch known as the "Brazda lui Novac de Sud" remain uncertain. The absence of any evidence for Late
Roman forts or settlements along its course and south of it rather suggests a later, probably medieval, date. ==See also==