From the Wikipedia page [1]
Angoumois (French pronunciation: [ɑ̃ɡumwa]), historically the County of Angoulême, was a county and province of France, originally inferior to the parent duchy of Aquitaine, similar to the Périgord to its east but lower and generally less forested, equally with occasional vineyards throughout. Its capital was Angoulême with its citadel and castle above the River Charente.
It almost corresponds to the Charente Department which also takes in the east of the coastal comté de Saintonge.