During the “Pax Romana” the region became more secure and the inhabtants were encouraged to settle on the plains. The arrival of Barbarians, Visigoth and Lombardian troop in the 5th Century forced populations to flee and seek refuge back on the higher ground. In the middle age (10th Century), these eagles’nests began to take on the shape of villages. These strategic places on the rocks (Saignon, Gordes) and hills (Menerbes, Lacoste) were initially occupied by “oppidum” or sometimes, Roman forts. The houses were grouped around the “cast rum”, which was there to protect the population. This was the beginning of the Luberon’s hilltop villages.