There is little documentary evidence for the trades and crafts which flourished in Cork in the thirteenth and fourteenth centuries, but is seems likely that they were similar to those found in other Irish and European cities of the same period. The documentary evidence contains many references to mills, both within and outside the walls of Cork; many of these mills were associated with ecclesiastical foundations. A particularly important mill was Droop's Mill which stood on present-day Liberty Street alongside the channel of the Lee which separated the south island from Dungarvan. There are many references to Droop's Mill right up to the seventeenth and eighteenth centuries.
Custom returns from Ireland in the thirteenth and fourteenth centuries show that Cork was regarded as the principal port of south-west Ireland. The 'port' would have been situated on the river channel separating the north and south islands and to the east of the central bridge. It's position would have corresponded approximately to present-day Castle Street. The main imports to Cork were wine, cloth and spices, while the principal exports were wool, grain, beef and other agricultural produce from the countryside surrounding the city.
This prosperity began to decline during the Gaelic and Gaelicised Anglo-Norman resurgence of the mid-fourteenth century, and Cork thus requested exemptions from its annual fee farm payment to the Crown during this period. The prosperity of the city suffered a devastating blow with the arrival of the Black Death in 1349. It was further impoverished by the need to defend itself from attack by the native population outside the city and was severely damaged by a serious fire in or around 1354. This period of relative decline in the fortunes of the city continued well into the fifteenth century.