The next three years were occupied in the subjugation of south-eastern Germany. Marching eastward through Suabia, whose warriors he compelled to accompany him to the field, Charles advanced against the Bavarians. After severe fighting, lasting over three campaigns, he returned in triumph with much plunder, a troop of hostages, and the submission of duke Hukbert. The allegiance of the Bavarians was still very insecure, but something had been done to enforce the long-forgotten suzerainty of the Franks. Alarmed by the subjection of Bavaria, the Suabian duke Lantfrid rebelled, but Charles slew him in battle, and refused to appoint any duke in his stead, in order that Suabia might more easily amalgamate with the neighbouring districts when it had lost the prince whose title symbolised its separate unity (730). While Charles worked with the sword against the eastern Germans, he did not neglect the other great means of binding them to the Frankish realm. [Sidenote: Mission of Boniface to Germany.] It was during the time of his Saxon and Bavarian wars that he lent his protection to the zealous West-Saxon monk Winfrith, the indefatigable preacher and organiser who won the name of the ‘Apostle of Germany’ by his long life-work among the Bavarians, Thuringians, and Hessians. After spending some time with bishop Willibrord at Utrecht, Winfrith had started eastward to find newer and wilder fields for his activity. He fixed himself first among the Hessians where no missionary had been seen since the death of St. Suidbert.[44] Here he met with such success that the whole land was soon reckoned Christian. Pope Gregory II., hearing of his triumphs, sent for him to Rome, and consecrated him missionary bishop of all Transrhenane Germany. After swearing implicit obedience to the Apostolic See for himself and all his converts, Winfrith—or as he is more often called in his later years Boniface—returned to the North with a papal letter of credence recommending him to the Mayor of Austrasia. Charles undertook the support of the new bishop with the greatest zeal: ‘without the aid of the prince of the Franks,’ wrote Boniface, ‘I should not be able to rule my church nor defend the lives of my priests and nuns, nor keep my converts from lapsing into pagan rites and observances.’ It was the fear of the wrath of Charles that kept the wild Hessians and Thuringians from murdering the unarmed missionary, when he came among them with his life in his hand, and hewed down the holy oak of Woden at Fritzlar in the presence of thousands of heathen spectators. For the next thirty-one years (723-54) Boniface went forth conquering and to conquer, churches and abbeys rising everywhere beneath his hand, in the regions where the Christian name had never before been known. Footnote 44: See p. 263.