When the insurgents under Duke Otto were joined by the Thuringians, Henry was compelled in 1074 to release Magnus and to make a number of concessions as the price of the peace of Gerstungen; which, however, was short-lived, as the peasants employed in pursuance of its terms in demolishing the forts, desecrated the churches and violated the ducal tombs.
The Thuringians are first mentioned by Vegetius Renatus about A.D.
It remained under the direct rule of the Frankish kings until 634, when Radulf was appointed duke of the Thuringians by King Dagobert I.
About this time the conversion of the Thuringians to Christianity was begun by British missionaries and continued by St Boniface, who founded a bishopric at Erfurt.
During the 1 rth century the Thuringians refused to pay tithes to Siegfried, archbishop of Mainz, and this was probably one reason why they joined the rising of the Saxons against the emperor Henry IV.
We are accustomed to look upon him chiefly as a missionary; but his completion of the conversion of the peoples of central Germany (Thuringians and Hessians) and his share in that of the Frisians, are the least part of his life-work.
In 531 Theuderich killed Hermannfried, king of the Thuringians, a former ally, with whom he had quarrelled, conquered hi~ kingdom, and added its southern portion to his own possessions.
Rupert, bishop of Worms, had already made some progress in the work of converting the Bavarians and Alamanni, as had Willibrord among the Thuringians when St Boniface appeared in Germany in 717.
Having been recognized as king by the Saxons, the Thuringians and the nobles of Lorraine, the new king was able to turn his attention to the affairs of government, but on the whole his reign was an unfortunate one for Germany.
Under Ottos leadership the Thuringians joined the rising, which soon spread far and wide.
The Saxons and the Thuringians were soon in arms, and they were joined by those warlike spirits of Germany to whom an age of peace brought no glory and an age of prosperity brought no gain.
Thus, when the Anglo-Saxon, Winfrid, surnamed Boniface, appeared in the kingdom of the Franks as papal legate in 723, to romanize the existing church of the time, neither the Franks, the Thuringians, the Alemanni nor the Bavarians could be considered as pagans.
In 531 the Thuringians in the centre of Germany were brought into subjection by his eldest son, King Theuderich, and about the same time the Bavarians were united to the Franks, though preserving a certain autonomy.