The French nobility plays a prominent role in most Crusades aimed at restoring Christian access to the Holy Land.

French knights make up the bulk of the steady flow of reinforcements throughout the two-hundred-year span of the Crusades, in such a fashion that the Arabs uniformly refer to the crusaders as Franj caring little whether they really come from France.

The French Crusaders also import the French language into the Levant, making French the base of the lingua franca (lit. "Frankish language") of the Crusader states.

French knights also comprise the majority in both the Hospital and the Temple orders.

The latter, in particular, hold numerous properties throughout France and by the thirteenth century were the principal bankers for the French crown, until Philip IV annihilates the order in 1307.

The Albigensian Crusade is launched in 1209 to eliminate the heretical Cathars in the southwestern area of modern-day France.

In the end, the Cathars are exterminated and the autonomous County of Toulouse is annexed into the kingdom of France.

Later French kings expand their domain to cover over half of modern continental France, including most of the north, center and west of France.

Meanwhile, the royal authority become more and more assertive, centered on a hierarchically conceived society distinguishing nobility, clergy, and commoners.