The Siege of Pemaquid (August 2–3, 1689) was a successful attack by a large band of Abenaki Indians on the English fort at Pemaquid, Fort Charles, then the easternmost outpost of colonial Massachusetts (present-day Bristol, Maine). The French-Abenaki attack was led by Jean-Vincent d'Abbadie de Saint-Castin and Father Louis-Pierre Thury and Chief Moxus. The fall of Pemaquid was a significant setback to the English. It pushed the frontier back to Casco (Falmouth), Maine.