In around AD 43, a large legionary fortress was begun, which was progressively fortified with stone walls, gates, and turrets, along with more permanent barracks, officers' quarters and administrative buildings.

The fortress was made smaller in the early 2nd century but remained an auxiliary base which helped define and defend the north-eastern limits of the Roman Empire for a further 200 years.

Tacitus mentions the name in ten different passages of his Histories, describing troop movements, retreats, battles, defections and defeats during the turbulent year of 69 CE.

[6] Around 575 he wrote Book II of his History of the Franks and section 9, quoting a now lost work by Sulpicius Alexander about events in 388, tells of how "Quintinus crossed the Rhine with his army near the stronghold of Neuss, and at his second camp from the river he found dwellings abandoned by their occupants and great villages deserted.

A variety of Roman artifacts had been found in the town through the 17th and 18th centuries, including two gravestones belonging to the XX and XVI Legions and one placed by a veteran of an auxiliary unit.

In 1844 they carried out excavations at Reckburg, discovering a small Roman fort, and in 1845 the Neuss Municipal Museum was begun, to display the growing quantity of finds.

[8] Fresh energy was injected in 1877 when a new generation of enthusiastic archaeologists founded the 'Vereins für Altertumskunde und Geschichte' (Association for Antiquities and History), whose members included Oskar Rautert and the 23 year old Constantin Koenen [de].

Koenen pursued a theory that it was to the south of the town, and in 1886 got permission from the Bonn Provincial Museum to make a test excavation on open ground towards the area where the Rhine is joined by the river Erft.

[10] Koenen's excavations had revealed a 'playing card' shaped stone-walled rectangular fortress with rounded corners, turrets at intervals and substantial gates on each of the 4 sides.

It was dated to the period from the mid-first century, when Emporer Claudius was consolidating the border along the Rhine Valley, and then moving the legions north-west to enable the expansion of Rome across the sea to Britain.

[11] Through the 1950s there was significant urban expansion at Neuss and from 1955 this included works to develop the district of Gnadental, along with a road scheme, near the area of the fortress.

In 1955 the Rhineland State Museum undertook further archaeological digs in advance of the construction works, funded initially by the city, and from 1957 by the Deutsche Forschungsgemeinschaft (German Research Foundation).

Until such time as a more comprehensive review of the camps is published, this account is largely the terminology from the 1980s, which in most cases means interpreting excavations from the early 1960s.

[18] This final phase of the Legionary fortress was the one that was most in evidence during Koenen's excavations of the late 19th century and is the layout that was recreated in a 1:200 scale model of the fortress, made between 1989 and 2006,[20] which is now on display in Neuss at the training center of the State Office of Police NRW (LAFP)[21] By around AD 104 (and possibly as early as AD 95) the Legio VI Vitrix had departed from Novaesium.

By AD 104 the central area of the old Legionary fortress was being remodelled as a smaller auxiliary camp traditionally indicated as Camp H. There are indications it may have been a base for a cavalry unit (as happened at Xanten and Bonn), and a gravestone of a rider from ala Afrorum veterana, dated around 100, gives a possible candidate for the Ala (Roman cavalry unit).

However, it had occupation over at least up to AD 256, when an invasion of Franks caused major destruction, and may have been completely destroyed in 275 during incursions following the downfall of the Gallic Empire.

Homes and businesses strung themselves along the roads leading up to the camp but many might expect to follow the legion when it moves on, and may leave little by way of archaeological remains.

[23] Unlike the Canabae, the Vicus (unplanned civilian town in the vicinity of the Camp) that grew up near Novaesium was not under military control and might be expected to have become a more permanent feature of the landscape.

Lots of individual finds and sites have been excavated around the centre of modern-day Neuss, suggesting it was the precursor to the later town, but it has not yet been possible to build a coherent picture of the scale and nature of the settlement, or its continuity into later periods.