To supplement the talk by Jonathon Hooton, here is an article about the Glaven Ports. I never thought I would include an article from the Fishing Times but here it is, and I think it is pretty good. It describes the rise of the three ports during medieval times and the types of goods that flowed through them. It was interesting to read about the taxes that were incurred on the goods - how much of a levy did the parson and the King get? It also goes into more detail regarding the conflict with the Hanseatic League. There is also detail on how the ports fell into decline. To find out the answers to these questions and more information please select the following link:
https://fishingnews.co.uk/features/the-glaven-ports-long-trips-from-small-places/