general Ricimer reached a treaty with them, and in 476 Genseric was able to conclude a "perpetual peace" with Constantinople. Relations between the two states assumed a veneer of normality. From 477 onwards, the Vandals produced their own coinage, restricted to bronze and silver low-denomination coins. The high-denomination imperial money was retained, demonstrating in the words of Merrills "reluctance to usurp the imperial prerogative". Although the Vandals had fended off attacks from the Romans and established hegemony over the islands of the western Mediterranean, they were less successful in their conflict with the Berbers. Situated south of the Vandal kingdom, the Berbers inflicted two major defeats on the Vandals in the period 496–530. Domestic religious tensions Differences between the Arian Vandals and their Trinitarian subjects (including both Catholics and Donatists) were a constant source of tension in their African state. Catholic bishops were exiled or killed by Genseric and laymen were excluded from office and frequently suffered confiscation of their property. He protected his Catholic subjects when his relations with Rome and Constantinople were friendly, as during the years 454–57, when the Catholic community at Carthage, being without a head, elected Deogratias bishop. The same was also the case during the years 476–477 when Bishop Victor of Cartenna sent him, during a period of peace, a sharp refutation of Arianism and suffered no punishment. Huneric, Genseric's successor, issued edicts against Catholics in 483 and 484 in an effort to marginalise them and make Arianism the primary religion in North Africa. Generally most Vandal kings, except Hilderic, persecuted Trinitarian Christians to a greater or lesser extent, banning conversion for Vandals, exiling bishops and generally making life difficult for Trinitarians. Decline According to the 1913 Catholic Encyclopedia: "Genseric, one of the most powerful personalities of the "era of the Migrations", died on 25 January 477, at the great age of around 88 years. According to the law of succession which he had promulgated, the oldest male member of the royal house was to succeed. Thus he was succeeded by his son Huneric (477–484), who at first tolerated Catholics, owing to his fear of Constantinople, but after 482 began to persecute Manichaeans and Catholics." Gunthamund (484–496), his cousin and successor, sought internal peace with the Catholics and ceased persecution once more. Externally, the Vandal power had been declining since Genseric's death, and Gunthamund lost early in his reign all but a small wedge