Some of these features appear in the work of the Saxon Willibrord among the Frisians, but are more largely illustrated in the career of St. Boniface-Winfried. Willibrord moved under the authority of Rome; the varying fortunes of his labours were connected with the enterprises of Pippin of Heristal, the father of Charles Martel. They advanced with the power of that Frankish potentate. But after his death, during the strife between Neustria and Austrasia, the heathen Frisian king Radbod drove back Christianity as he enlarged his dominion at the expense of the divided Franks. Later, Charles Martel conquered him, and the Frankish power reached (718) to the Zuyder Zee. Under its protection Willibrord at last founded the bishopric of Utrecht (734). He succeeded in educating a native clergy; and his labours had lasting result among the Frisians who were subject to the Franks, but not among the free Frisians and the Danes. Evidently there was no sharp geographical boundary between Christianity and heathendom. Throughout broad territories, Christian and heathen practices mingled. This was true of the Frisian land. It was true in greater range and complexity of the still wider fields of Boniface’s career. This able man surrendered his high station in his native Wessex in order to serve Christ more perfectly as a missionary monk among the heathen. He went first to Frisia and worked with Willibrord, yet refused to be his bishop-coadjutor and successor, because planning to carry Christianity into Germany. Strikingly his life exemplifies Anglo-Saxon faculties working under the directing power of Rome among heathen and partly Christian peoples. On his first visit to Rome he became imbued with the principles, and learned the ritual, of the Roman Church. He returned to enter into relations with Charles Martell, and to labour in Hesse and Thuringia, and again with Willibrord in Frisia. Not long afterwards, at his own solicitation, Gregory II. called him back to Rome (722), where he fed his passion for punctilious conformity by binding himself formally to obey the Pope, follow the practices of the Roman Church, and have no fellowship with bishops whose ways conflicted with them. Gregory made him bishop over Thuringia and Hesse, and sent him back there to reform Christian and heathen communities. Thus Gregory created a bishop within the bounds of the Frankish kingdom--an unprecedented act. Nevertheless, Charles, to whom Boniface came with a letter from Gregory, received him favourably and furnished him with a safe conduct, only exacting a recognition of his own authority.