By the end of the 7th century and the beginning of the 8th, Merovingian authority throughout the Frankish world had been seriously diminished by internal divisions among rival noble factions. Although the dynasty would retain possession of the crown until 751, it was effectively replaced by a rising power, the Carolingian family, which controlled the office of mayor of the palace. The Carolingians, or Pippinids as they are known in their early days, first rose to power in the second decade of the 7th century when they assisted Chlothar II in the overthrow of Queen Brunhild. Their leader, Pippin I, was rewarded with the office of mayor, and his descendants would use the office as a means to enhance their power. However, both the Merovingians and Carolingians faced the claims of rival aristocratic families, including the Agilolfings, who also held the office of mayor of the palace. The victory of Pippin II over the Agilolfing mayor at the battle of Tertry in 687 reunited the kingdom in the name of the Merovingian king Theuderic IV and signaled the rising power of the Carolingians. Pippin’s son, Charles Martel, after a struggle with Pippin’s widow, assumed his father’s position and came to be the leading figure in the realm. His position was so secure that he was able to rule during the last three years of his life without a Merovingian king on the throne, and he also was able to divide the kingdom between his two sons as the Merovingians had traditionally done.

The early Carolingians consolidated control over the Frankish heartland and the duchies east of the Rhine, partly by supporting the missionary activities of churchmen who espoused Roman hierarchical forms of ecclesiastical organization that favoured political centralization; looser indigenous and Irish ecclesiastical structures meanwhile lost ground. Frankish penetration followed a pattern in which communities or churches were settled on land newly won from forest or marsh and granted them by their Carolingian protectors. Thus, from Frisia in the north to Bavaria in the south, religious, economic, and political penetration went hand in hand. A distinguished part was played by Anglo-Saxon missionaries, who linked the Frankish world not only with the high culture of their homeland but also with Rome. One of the most prominent of these was St. Willibrord (c. 658–739), who worked as a missionary and Frankish agent among the Frisians and later the Thuringians. Of even greater significance was Willibrord’s disciple St. Boniface (c. 675–754), the “apostle of Germany,” who preached the Word to the pagan Germans and introduced religious reform to the Frankish church. Supported by Charles Martel, Boniface led missions into Franconia, Thuringia, and Bavaria, where he founded or restructured diocesan organization on a Roman model. In 742, with the support of the new mayors of the palace Pippin and Carloman, he played a large part in the first council of the new German church. By the time of his martyrdom at the hands of northern Frisians, all the continental Germanic peoples except the Saxons were well on the way toward integration into a Roman-Frankish ecclesiastical structure.

Boniface’s missionary activities and religious reforms also influenced political developments in the Frankish kingdom. His close contact and frequent correspondence with the pope in Rome reinforced a developing trend in the Frankish world that involved the increasing devotion to St. Peter and his vicar. When Charles Martel’s son and successor, Pippin, sought justification for his usurpation of the Frankish throne in 750, he appealed to Pope Zacharias, asking whether the person with the title or the power should be king. In the following year, Pippin assumed the throne and was crowned by the bishops of his realm, including, according to one account, the pope’s representative in the Frankish kingdom, St. Boniface. Three years later, Pope Stephen II traveled to Pippin’s kingdom to seek aid from the king against the Lombards. While there, Stephen strengthened the alliance with the Carolingians and Pippin’s claim to the throne when he crowned Pippin and, according to some accounts, Pippin’s sons Carloman and the future Charlemagne.