Chesters fort was, like most forts on Hadrian’s Wall, planned and built after construction of the wall proper had started. Next to the Praetorium are the foundations of Turret 27b as the fort was built directly above the line of the wall from its east to west gates. It’s Roman name, Cilurnum, suggests a swirling cauldron or pool and may refer to the nearby river Tyne.
As you walk from the modern car park by the visitors centre past the remains of the north gate you are walking into what was the Roman Empire.

The earliest garrison was a regiment of cavalry; the Ala Augusta ob Virtutem Appellata “named Augusta on account of its valour”. Most of the early remains of the fort were lost when it was excavated in the 19th century and now the earliest remains to be seen are those of the fort defences, the Principia, and parts of the bath house. There are however earlier remains still uncovered under the Praetorium and the visible barrack blocks. The fort was 5 ¾ acres in size

By AD 146 the original cavalry unit had been moved elsewhere. A discharge diploma dated to this year was found in the eastern guardhouse of the south gate. The discharge was for an auxiliary soldier and its wording suggests it belonged to an infantryman.
In the early second century a unit of the first cohort of Dalmatians was stationed at Cilurnum, and later, under the reign of Antoninus Pius (138-61) a vexillation of the 6th legion was stationed there as the main garrison probably moved north to the Antonine Wall.

Aurelia, the daughter of the commanding officer of the 1st Cohort of Vangiones died while he was stationed at the fort, and her name suggests they were there in the late second century. In 184 the governor of Britain was Ulpius Marcellus and at this time the 2nd Ala of Asturians (Ala II Astorum) were based at Chesters. They were still there at the end of the 4th century.

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