The name Manchester has its origins in the name of the Roman settlement, Mamucium, which means camp (castra) by the breast like hill (mamm). As part of his campaign to expand Roman influence north in AD79, the Roman general Agricola ordered that a fort be established at the confluence of the rivers Medlock and Irwell; a strategic position to protect and maintain communications between the main Roman settlements at York, Chester, Ribchester, Lincoln and the South of England. The original fort was constructed of wood, the later fort being made from stone and located further down-stream from the original one.

The layout of the fort was the usual rectangle with rounded corners surrounded by a double 'v' shaped ditch with a strong gatehouse on each of the four walls and towers at the corners. The internal layout of the fort followed the standard pattern:

• the HQ, called the Principia, was located in the centre of the fort. This building was the unit's administrative centre and included a strong room for the unit's money and wages and also a shrine for the unit's standards and battle honours.

• the main road, called the Via Praetoria, ran from the Principia directly ahead to the front gate called the Porta Praetoria. Another road running in front of the Principia between the two side gates was called the Via Principalis. There was also a another road that led from the back of the Principia to the back gate called the Via Decumana. (see Roman Fort for an interactive illustration)

• next to the Principia was the Praetorium where the commander and his family lived.

• on the other side of the Principia were the granaries where the unit's food supplies were kept. The granaries had raised floors and were ventilated to help protect against pests and damp.

• the barracks were on the other side of the Via Praetoria from the Principia, either side of the Via Praetoria

• behind the Principalis were store rooms and workshops.

• the bathhouse was located outside the fort down towards the river.

The fort would have been the base for between 500 and 1,000 auxiliary soldiers. The auxiliaries were the light troops, like spearmen and archers, or cavalry; rather than the heavily armed legionary infantry.

The course of the main road through the settlement, connecting Ribchester in the north and Chester in the west, can still be identified as the modern Deansgate and Chester Road. A Roman altar has been found on Chester Road on the south side of the ford over the river Medlock. Travellers would have used this to ask the gods for a safe journey. Other roads radiated from the fort towards Wigan; York via Castle Shaw; Melandra (Glossop) en-route to Lincoln; and Stockport on the way to the spa at Buxton and the South of England.

A Vicus (civilian settlement) grew up around the fort where the families of the legionnaires, tradesmen and craftsmen lived; drawn to the settlement by the relative security offered by the fort's garrison.

The settlement would have been an important centre of activity and was occupied until around the middle of the 3^rd century, about the time that the Roman military forces withdrew from Britain.