There were, however, some difficulties connected with the frequent English pilgrimages to Rome; too frequent according to Alcuin for the good repute of the Anglo-Saxon dames who engaged in them; and too frequent, as the tax collectors of Charles the Great considered, by reason of the number of merchants who, under the guise of holiness, transacted a profitable business in the transport of specie and merchandise. These difficulties were, however, set right by a friendly letter from Charles to the effect that true pilgrims should receive all due protection from him, but that merchants masquerading as pilgrims must pay the regular customs dues. This letter, written in 796, was accompanied by the present of a belt, a Hunnish sword and two silken vestments, part of the huge spoil taken in the previous year from the robber hold of the Avars. It seems to have healed an old estrangement between the two kings dating from 789, the result of the failure of matrimonial negotiations between them. Charles had solicited the hand of Offa’s daughter for his son and namesake, and Offa had been willing to consent, on condition that Charles’s daughter, Bertha, should become the bride of his son, Ecgferth. On this point, however, the negotiations broke down, owing to Charles’s well-known reluctance to part with any of his daughters. For a short time the relations between the two kingdoms were sorely strained, and decrees forbidding the entrance of merchants were issued by either angry sovereign, but gradually the dispute died down, perhaps partly owing to the mediation of Alcuin, who was English by birth and loyal to his English friends, but Frank by adoption and a true subject to Charles. At last, as we have seen, all wounds were healed by the application of an Avar baldric, a sword and two mantles. Offa died in 796, and his son and successor Ecgferth followed him to the grave in four months. This untimely death of a young and hopeful prince was, according to monastic writers, a punishment for the many crimes of his father, especially for the execution of the East Anglian Ethelbert. Cenwulf, who succeeded to the Mercian throne, was not of Offa’s line, though like him a collateral descendant of Penda. Of his reign, which lasted well on into the ninth century (796–821), nothing need here be said, save that in its third year he invaded Kent, which had revolted from his rule and set up a rival king named Edbert Pren, possibly a descendant of the old Kentish line. Edbert was defeated and taken prisoner by the soldiers of Offa, who, after cutting out his tongue and chopping off his hands, sent him as a prisoner into Mercia. With all its vaunted prosperity, the central kingdom does not seem to have made great progress in civilisation since the days of Penda. * * * * *