Boulogne-sur-Mer

Boulogne stands on the Channel at the mouth of the Liane. Its fortified upper town overlooked the harbour below, tying the defence of the city to command of the sea. Close to England and to the English possession of Calais, the port occupied a vulnerable place in the wars between the two crowns.

Henry VIII's army captured Boulogne in September 1544 after a long and costly siege. The English strengthened the upper town and built new works to protect the harbour, but French forces remained close by. A new agreement returned Boulogne to France in 1550. The English harbour works, intended to protect shipping, later contributed to the silting of the channel, and the port required further works in the eighteenth century.