Medieval trade networks (Bristol, Dublin, Drogheda, Chester)
. https://mega.nz/file/0ioSTSbJ#SnwLCRRNQLWq0_1y8bPlYDC0R32RM1_u1Mkni_YLx-0
Trade with Ireland: https://www.journals.uchicago.edu/doi/pdf/10.1086/252861

History of Drgoheda Port: de Verdon, de Lacy and others
. https://www.droghedaport.ie/history,-heritage-and-archives/a-brief-history-of-drogheda-port/history-of-drogheda-port/

During the unification period Drogheda merchants traded mostly with other Irish ports. Goods were shipped on a regular basis to Cork, Kilkenny, Wexford, Kinsale, Youghal and also to Ulster ports such as Carrickfergus. Although the documentary references to the overseas trade of Drogheda are sparse the town did have extensive trading connections with Flanders, Gascony, Bordeaux, Bristol and Chester. Ships from Drogheda sailed to Gdansk in 1384, Iceland in 1458 and Lisbon in 1480.

Trade Routes between Chester and Ireland
. https://chester.shoutwiki.com/wiki/Chester_and_Ireland