Having fixed the seat of his government in Austrasia, as the more German and warlike portion of his dominions, he named dependents of his own, and subsequently his two sons, Drogo and Grimwald, to rule as mayors in the two other divisions of the empire. He gave the greatest proof of his power and popularity by restoring the assemblies of the Campus Martius, a purely German institution, which under the romanising Merovingian monarchs had gradually declined. At these annual meetings, which were held on the 1st of March, the whole nation assembled for the purpose of discussing measures for the ensuing year. None but a ruler who was conscious of his own strength, and of an honest desire for the welfare of his people, would have voluntarily submitted himself and his actions to the chances of such an ordeal.
As soon as he had firmly fixed himself in his seat, and secured the submission of the envious seigneurs, and the love of the people, who looked to him as the only man who could save them from the evils of anarchy, he turned his attention to the re-establishment of the Frankish Empire in its full extent. The neighbouring tribes, which had with difficulty, and for the most part imperfectly, been subdued by Clovis and his successors, were ready to seize upon every favourable occasion of ridding themselves of the hated yoke. Nor were the poor imbecile boys who bore the name of kings, nor the turbulent mayors and seigneurs who were wholly occupied with plotting and counterplotting, railing and fighting against one another, at all in a position to call the subject states to account, or to excite in them the desire of being incorporated with an empire harassed and torn by intestine dissensions. The Frankish Empire was in process of dissolution, and all the more distant tribes, as the Bavarians, the Alamanni, Frisians, Bretons, and Gascons, had virtually recovered their independence. But this partial decline of the Frankish power was simply the result of misgovernment, and the domestic feuds which absorbed the martial vigour of the nation; and by no means indicated the decline of a military spirit in the Frankish people. They only needed a centre of union and a leader worthy of them, both of which they found in Pepin, to give them once more the hegemony over all the German tribes, and prepare them for the conquest of Europe. The Frisians were subdued, or rather repressed for a time, in 697 A.D., after a gallant resistance under their king Ratbod; and about twelve years afterwards we find the son of Pepin, Grimwald, forming a matrimonial alliance with Theudelinda, daughter of the Frisian monarch; a fact which plainly implies that Pepin desired to cultivate the friendship of his warlike neighbours. The Swabians, or Alamanni, were also attacked and defeated by Pepin on their own territories; but their final subjection was completed by his son Charles Martel.
The wars carried on by Pepin with the above-mentioned nations, to which in this place we can only briefly allude, occupied him nearly twenty years; and were greatly instrumental in preserving peace at home, and consolidating the foundations of the Carlovingian throne. The stubborn resistance he met with from the still heathen Germans, was animated with something of that zeal, against which his great descendant Charlemagne had to contend in his interminable Saxon wars; for the adoption of Christianity, which was hated, not only as being hostile to the superstitions of their forefathers, but on account of the heavy taxes by which it was accompanied, was always made by Pepin the indispensable condition of mercy and peace. But, happily for the cause of Gospel truth, other means were used for the spread of Christianity than the sword and the scourge; and the labours of many a zealous and self-sacrificing missionary from Ireland and England served to convince the rude German tribes that the warrior-priests whom they had met on the battle-field, and the greedy tax-gatherers who infested their homes, were not the true ambassadors of the Prince of peace. And Pepin, who was by no means a mere warrior, was well aware of the value of these peaceful efforts; and afforded zealous aid to all who ventured their lives in the holy cause of human improvement and salvation. The civil governors whom he established in the conquered provinces were directed to do all in their power to promote the spread of Christianity by peaceful means; and, to give effect to his instructions, Pepin warned them that he should hold them responsible for the lives of his pious missionaries.