For a long time, in spite of official decisions in favour of uniting, Clermont and Montferrand remained separate towns, each on one side of the current Avenue de la République, separated by a space which has only been developed in recent years. Clermont and Montferrand were very different towns historically.

Where Montferrand was founded at the beginning of the XII century by the Counts of Auvergne along the lines of new towns in the Midi, Clermont’s history dates back to antiquity and it rapidly took on the mantle of an Episcopal town. The earliest mention of the existence of Clermont can be found in work by Strabon, at the beginning of the first century. At the time the town was called Nemossos and designated as an Arvernian "metropolis", thereby showing its importance. In the middle of the first century, it took the name of Augustonemetum and saw a period of growth which ended in the middle of the third century.