Harfleur, siege of

French siege of English-held port on the mouth of the Seine, late 1415. Henry V seized the port at great cost Aug–Sept 1415 and the French maintained vigorous efforts to recapture the town, even after their defeat at Agincourt. Henry tried to promote Harfleur as a permanent English possession on French soil, like Calais, and went to great lengths to encourage English immigration. The English held until 1435 when it was retaken by the French for 5 years, before passing back into English possession 1440–49.