The Phoceans and Etruscans made their cultural mark on the North-Mediterranean area. Finished products, raw materials, ideas, beliefs and ritual practices circulated widely and played their part in the rapid evolution of Mediterranean societies. 5 sites in the north-western Mediterranean (Tarquinia, Aléria, Marseille, Lattes / La Monédière, Ampurias), have been selected to develop an innovative transdisciplinary study combining (1) a technical approach to archaeological material, ( 2) chemical (GC-MS) and proteomics analyzes, (3) archaeobotanical study. The objective is to identify the plant and animal raw materials used in Etruscan, Phocean and Gallic rituals for the same period (6th-4rd century BC) and to help to shed light on the gestures and meaning of ritual (rite of commensality), by using data which complements the material/ physical evidence usually provided by archeology, and by a comparative approach.