Under the protection of the powerful Frankish mayor of the palace, Charles Martel, Boniface carried on his missionary work with such zeal that he succeeded in bringing all the older Christian communities which had been established by the Irish missionaries under the papal control, as well as in converting many of the more remote German tribes who still clung to their old pagan beliefs. His energetic methods are illustrated by the story of how he cut down the sacred oak of Odin at Fritzlar, in Hesse, and used the wood to build a chapel, around which a monastery soon grew up. In 732 Boniface was raised to the dignity of Archbishop of Mayence and proceeded to establish, in the newly converted region, the German bishoprics of Salzburg, Regensburg, Würzburg, Erfurt, and several others; this gives us some idea of the geographical extent of his labors. [Sidenote: Boniface reforms the church in Gaul and brings it into subjection to the pope.] After organizing the German church he turned his attention, with the hearty approval of the pope and the support of the Frankish rulers, to a general reformation of the church in Gaul. Here the clergy were sadly demoralized, and the churches and monasteries had been despoiled of much of their property in the constant turmoil of the time. Boniface succeeded, with the help of Charles Martel, in bettering affairs, and through his efforts the venerable church of Gaul, almost as old as that of Rome itself, was brought under the supremacy of the pope. In 748 the assembled bishops of Gaul bound themselves to maintain the Catholic unity of faith and follow strictly the precepts of the vicar of St. Peter, the pope, so that they might be reckoned among Peter's sheep. General Reading.--The best history of the monks to be had in English is MONTALEMBERT, _The Monks of the West from St. Benedict to St. Bernard_ (Longmans, Green & Co., 6 vols., $15.00). The writer's enthusiasm and his excellent style make his work very attractive. The advanced student will gain much from TAYLOR, _Classical Heritage of the Middle Ages_ (The Macmillan Company, $1.75), Chapter VII, on the origin and spirit of monasticism. See also HARNACK, _Monasticism_ (Scribners, 50 cents). The works on church history referred to at the end of the preceding chapter all contain some account of the monks. CHAPTER VI CHARLES MARTEL AND PIPPIN [Sidenote: Charles Martel, Frankish mayor of the palace, 714-741.] 24. Just as the pope was becoming the acknowledged head of the Western Church, the Frankish realms came successively under the rule of two great statesmen, Charles Martel and his son Pippin the Short, who laid the foundation of Charlemagne's vast empire. [Sidenote: Difficulty of holding together a kingdom in the early Middle Ages.]