Æthelbald, reigned from 716 to 757. For the first few years of his reign he had to face two strong rival kings, Wihtred of Kent and Ine of Wessex. But when Wihtred died in 725, and Ine abdicated in 726 to become a monk in Rome, Æthelbald was free to establish Mercia's hegemony over the rest of the Anglo-Saxons south of the Humber. Æthelbald suffered a setback in 752, when the West Saxons under Cuthred defeated him, but he seems to have restored his supremacy over Wessex by 757. In July 2009, the Staffordshire Hoard of Anglo-Saxon gold was discovered by Terry Herbert in a field at Hammerwich, near Brownhills and close to Lichfield in Staffordshire. Lichfield functioned as the religious centre of Mercia. The artefacts have tentatively been dated by Svante Fischer and Jean Soulat to around AD 600–800. Whether the hoard was deposited by Anglo-Saxon pagans or Christians remains unclear, as does the purpose of the deposit. Reign of Offa and rise of Wessex After the murder of Æthelbald by one of his bodyguards in 757, a civil war broke out which concluded with the victory of Offa, a descendant of Pybba. Offa (reigned 757 to 796) had to build anew the hegemony which his predecessor had exercised over the southern English, and he did this so successfully that he became the greatest king Mercia had ever known. Not only did he win battles and dominate Southern England, but also he took an active hand in administering the affairs of his kingdom, founding market towns and overseeing the first major issues of gold coins in Britain; he assumed a role in the administration of the Catholic Church in England (sponsoring the short-lived archbishopric of Lichfield, 787 to 799), and even negotiated with Charlemagne as an equal. Offa is credited with the construction of Offa's Dyke, which marked the border between Wales and Mercia. Offa exerted himself to ensure that his son Ecgfrith of Mercia would succeed him, but after Offa's death in July 796 Ecgfrith survived for only five months, and the kingdom passed to a distant relative named Coenwulf in December 796. In 821 Coenwulf's brother Ceolwulf succeeded to the Mercian kingship; he demonstrated his military prowess by his attack on and destruction of the fortress of Deganwy in Gwynedd. The power of the West Saxons under Egbert (King of Wessex from 802 to 839) grew during