Thouars

The viscounts of Thouars emerged in the late ninth century as officers of the count of Poitou, governing the Thouarsais of northern Aquitaine from Thouars castle. Probably sprung from Poitiers landowners, they grew rich on abbey patronage and Bressuire estates; Poitevin custom let the viscounty pass from brother to brother rather than directly from father to son.

Aimery IV of Thouars crossed the Channel with William the Conqueror and fought at Hastings in 1066. From 1150 to 1230 the family steered between the Capetian kings and the Plantagenets. Its most famous branch entered Brittany when Guy of Thouars married Duchess Constance in 1199, ruling jure uxoris and then regent for his daughter Alix in 1203—1206.

In the Hundred Years' War Thouars was seized by the Black Prince and later retaken for France by Bertrand du Guesclin. The line ended with a viscountess dying in 1397; the viscounty passed to Amboise and then the La Trémoille, who made it a duchy in 1563.