In 1257, Edmund joined his parents on their first visit to Germany, to pursue Richard's nominal or claimant title as king to the Holy Roman Empire, returning in January 1259. In 1264, after his father's capture at the Battle of Lewes, Edmund was held prisoner with his father at Kenilworth Castle, being released in September 1265. He and his father returned to Germany in August 1268, and according to a semi-mythical account written many years later, acquired a relic of the blood of Jesus Christ that had belonged to Charlemagne, before returning to England in August 1269. He is said to have given part of this relic to the monks of his father's foundation at Hailes Abbey in Gloucestershire, following a ceremony in September 1270, and part to Ashridge Priory, Hertfordshire.