Following the French Raid of 1338 the strengthening of the town’s defence system was ordered by King Edward III. The town was to be fully enclosed by stone walls, especially along the western quays, where wealthy merchants had built their houses. Due to a shortage of suitable stones, a compromise was found, which meant the integration of the merchants’ houses into the town wall.
Of course, the merchants were unwilling to lose their sea front warehouses, but by 1380 the doors and windows in the front of the houses were blocked up with stone or converted into arrow slits and gun ports, and they became part of the town’s defensive wall.
Henry Yevele, who oversaw improvements to the castle, probably was also involved in the construction of the Arcades. Wide arches were constructed that enforced the structure of the walls, which were then completed with parapets and machicolations.