Several large kingdoms were formed in the Viking-Age period, the best known settlements being in Ireland and York. Dublin became a thriving hub for western Viking expansion and trade. New discoveries of silver and other items show that traded commodities traveled vast distances, but how interconnected were these towns? And how much were they a part of a greater Viking network? In this episode, Dr. Cat Jarman is joined by Dr. Tom Horne, author of 'A Viking Market Kingdom in Ireland and Britain'.