Although paeolithic cave dwellings have been discovered in the hills of this region, the earliest "modern" history began around 1000 BC along the coast of the Mediterranean, which was occupied by the Ligurians.
In 500-400 BC, the Greeks set up trading posts at sites along the coast, including Antibes, Nice and Monaco. About the same time, the Celts from further North invaded Provence, and ended up mingling with the ancient Ligurians.
Three Celtic tribes, the Cavares, the Méminiens and the Voconces, once occupied the area that's now the department of the Vaucluse.
The Cavares were along the Rhone and Durance rivers and occupied the Pays d'Orange (Arausio), the Pays d'Avignon (Aouenion) and the Pays de Cavaillon. Around the 5th century BC the Cavares began trading with the Phoceans, who had penetrated up the Rhone from Marseille. The Cavares had a continued alliance with the Phoceans and then with Rome, eventually leading them to a futile attempt to stop Hannibal's crossing the Rhone in 218 BC. By the 2nd-century BC, the Cavares dominated the region from Cavaillon to Valence (Isére) [map] .
The Méminiens, one of the tribes in the Cavares confederation, were located northeast of Carpentras, on the southern flanks of Mont Ventoux.
In 122 BC, the Celts were defeated by the Romans, beginning the Gallo-Roman era of Provence. (Julius Caesar officially conquered Gaul in 58-51 BC, although the surrender of Vercingétorix still left the majority of the war-like Gaullish tribes still fighting, against the Romans and against each other.)
By the 1st century BC the Romans dominated Provence. The Cavares, the Méminiens and the Voconces were enveloped into the Narbonnaise, and following the division of Gaul into 17 provinces, they became part of the Viennoise province.