You can realise that when the country was in a very disturbed state, so that the king's authority could not easily and quickly be enforced, the lord who had many of these tenants or vassals could do very much as he pleased on his own territories. You will also realise that when men could no longer get justice from the central authority, which the king represented, they were only too grateful to get it from their feudal lord.
Divisions in Gaul
And the condition of Gaul under the Franks began to be a condition of general disturbance after the death of the great King Clovis. He died in 511 and he left his kingdom divided between his four sons. The youngest of these sons, by name Clotaire, lived longer than any of his brothers, but on his death, in 561, he in turn left four sons, and again there was division of the kingdom, claims were made by one and were resisted by another. There was continual civil war. Yet again, a few years later, there were new divisions amongst the children of one or other of these, and so it went until the kingdom was once more united, after 613, by the death or defeat of his rivals, under Clotaire II. Clotaire was nominally sovereign, yet still there were the subordinate kingdoms, each claiming some independence.
But during this century, when the Frankish conquerors were fighting with each other, the general condition of society had been altered. We have seen how the large landowners began drawing to themselves a body of vassals, and how they gradually became more independent of the king's authority. We have to notice at the same time that the power of the Church, in the hands of its bishops, was continually growing greater. The Church was constantly being enriched by donations of land given it by pious persons who deemed that they might find salvation by these gifts; and what made the Church the more powerful was the above-mentioned custom of granting "immunities."
The "immunities" were granted by the Crown, in return for some service done, or by way of payment of a debt, or as an act of mere friendliness; and the meaning of the "immunity" was that the land in respect of which it was granted was "immune" from the king's tax collectors or law officers. The Crown officials could not enter on it. The taxes were collected and the law administered by persons acting for the landowner. You see how this again would work towards making the great landowners independent of the Crown. And these "immunities" were largely given to the bishops in respect of the Church lands. The bishops thus grew to great independence and power, and they worked continually to have their own people, the subordinate clergy, subject to their own laws, the laws of the Church, and not to the laws of the Crown.
Now at the court of the Merovingian kings and also of the lesser kings, the chief officer and chief executor of the king's will was an official called "the Mayor of the Palace." He was everywhere a man of great influence and of high family. He acted not so much like an English Prime Minister as like the vizier, the chief officer, of an Oriental king.
As time passed, in the constant distractions of the kingdom and the weakening power of the central authority, the power of these high officials grew continually.
The distractions and the struggles between the lesser kingdoms in Gaul, and also between the nobles and the king, went on for another century. The contest which really settled the matter, for a while, was a battle at Tertry in 687, in which Pepin, Pepin II., as he was called, defeated the king's forces, and took the king prisoner. It was not, however, till the middle of the next century that the line of the Merovingian kings died out. All that while, however, they were practically dominated by Pepin, the victor at Tertry, and when their dynasty came to an end he became king of the Franks, and therewith founded a new dynasty, the Carolingian.
Charles Martel
Pepin came to the throne with powers derived from two sources. His family had held the great office of Mayor of the Palace in one of the subordinate kingdoms for nearly half a century, and he was also descended from a great bishop, Arnulf. Thus he had all the power of the Church on his side. Charles Martel, who succeeded him, gained an important victory over the Saracens at Tours in 732. That is a very notable event in our story, for it pushed back the Moors south of the Pyrenees again, and freed Christian Gaul from their danger. Further, this same Charles (Martel, or the Hammer, as he was called) served the Church of Rome faithfully in Germany, supporting a mission which Bishop Boniface was carrying on for the conversion of some of the still pagan German tribes to Christianity.