Cohesion as success factor of the Roman Legion

The Roman military instrument was one of the most successful and powerful in history. At the core of Rome’s military strength was their heavy infantry, the legion (from Latin legio "military levy, conscription"). A professional military force that was organized and reorganized several times along the Roman history (from a form of phalanx in the early ages to the more sophisticated manipular order) , and was characterized by its tactical flexibility, learning from their defeats and victories to counter the strenghts of their various enemies.

While the Roman military power was based on numbers and sheer strategy, the organization of their legions can be characterized by unity, discipline and cohesion. The military discipline of the legions was quite harsh. with a broad array of punishments. The unity was enforced by a well structured chain of command and ranks, symbols as the "aquila" or eagle of the legion (its loss was considered to be a serious embarrassment, and could led to the disbanding of the legion) and a personal bond to their commanders.

It was in Rome Army that for the first time the rank and place of soldiers were not based on citizenship, georaphical origin or wealth but on warfare experience and age. The legions were mixing people from all regions and origins, and integrating them in standardized and professionalized units. In this context it was key to ensure a strong cohesion of these units (so that norms of the units are in congruence with army objectives, more specifically the bonding of members to sustain their will and commitment to their unit) by adhesion to common martial values and a strong code of conduct. The influence of Roman religious and civic culture, gave the Roman legion consistent motivation and cohesion, at the heart of these values stood the Roman "virtus" or fierce valor, that was leading by example and stimulating the martial values of the Roman soldiers.