Charles Martel (; c. 688 – 22 October 741), Martel being an Old French sobriquet meaning "The Hammer", was a Frankish political and military leader who, as Duke and Prince of the Franks and Mayor of the Palace, was the de facto ruler of the Franks from 718 until his death. He was a son of the Frankish statesman Pepin of Herstal and a noblewoman named Alpaida. Charles successfully asserted his claims to power as successor to his father as the power behind the throne in Frankish politics. Continuing and building on his father's work, he restored centralized government in Francia and began a series of military campaigns that re-established the Franks as the undisputed masters of all Gaul. According to the contemporary Liber Historiae Francorum, Charles was "a warrior who was uncommonly ... effective in battle".
Charles gained a victory against an Umayyad invasion of Aquitaine at the Battle of Tours, and Charles is credited as an important factor in curtailing the spread of Islam in Western Europe. Alongside his military endeavours, Charles has been traditionally credited with an influential role in the development of the Frankish system of feudalism.
At the end of his reign, Charles divided Francia between his sons, Carloman and Pepin; Pepin became the first king of the Carolingian dynasty. Pepin's son Charlemagne, grandson of Charles, extended the Frankish realms and became the first emperor in the West since the Fall of the Western Roman Empire.
Charles, nicknamed "Martel" ("the Hammer") in later chronicles, was a son of Pepin of Herstal and his mistress, possibly second wife, Alpaida. He had a brother named Childebrand who later became the Frankish dux (that is, duke) of Burgundy. Charles was a great-grandson of Arnulf of Metz.
Older historiography commonly describes Charles as "illegitimate", but the dividing line between wives and concubines was not clear-cut in 8th-century Francia. It is likely that the accusation of "illegitimacy" derives from the desire of Pepin's first wife Plectrude to see her progeny as heirs to Pepin's throne.
By Charles's lifetime the Merovingians had ceded power to the mayors of the palace who controlled the royal treasury, dispensed patronage, and granted land and privileges in the name of the figurehead king. Pepin of Herstal had united the Frankish realm by conquering Neustria and Burgundy. Pepin was the first to call himself Duke and Prince of the Franks, a title later taken up by Charles.
In December 714 Pepin died. A few months before his death and shortly after the murder of his son Grimoald the Younger, he had taken the advice of Plectrude to designate as his sole heir Theudoald, his grandson by Grimoald. This was immediately opposed by the Austrasian nobles because Theudoald was a child of only eight years of age. To prevent Charles using this unrest to his own advantage, Plectrude had him imprisoned in Cologne, the city which was intended to be her capital. This prevented an uprising on his behalf in Austrasia, but not in Neustria.
Pepin's death occasioned open conflict between his heirs and the Neustrian nobles who sought political independence from Austrasian control. In 715 Dagobert III named Raganfrid as mayor of the palace over Neustria and Burgundy. On 26 September 715, Raganfrid's Neustrians met the young Theudoald's forces at the Battle of Compiègne. Theudoald was defeated and fled back to Cologne. Before the end of the year, Charles had escaped from prison and was acclaimed mayor of the palace over Austrasia. Dagobert died in 715, and the Neustrians proclaimed Chilperic II, the cloistered son of Childeric II, as king.
In 716, Chilperic and Raganfrid led an army into Austrasia intent on seizing the Pippinid wealth at Cologne. The Neustrians allied with another invading force under Radbod, King of the Frisians and met Charles in battle near Cologne, which was still held by Plectrude. Charles had little time to gather men or prepare, and the result was inevitable. Radbod held off Charles, while Chilperic and Raganfrid besieged Plectrude, where she bought them off with a substantial portion of Pepin's treasure. After that they withdrew. The Battle of Cologne was the only defeat of Charles's career.
Charles retreated to the hills of the Eifel to gather and train men. In April 716 he fell upon the triumphant army near Malmedy as it was returning to Neustria. In the ensuing Battle of Amblève, Charles attacked as the enemy rested at midday. According to one source, he split his forces into several groups which fell at them from many sides. Another suggests that while this was his intention, he then decided that given the enemy's unpreparedness, this was not necessary. In any event, the suddenness of the assault led them to believe they were facing a much larger host. Many of the enemy fled, and Charles's troops gathered the spoils of the camp. His reputation increased considerably as a result, and he attracted more followers. This battle is often considered by historians as the turning point in Charles's struggle.
Richard Gerberding points out that up to this time, much of Charles's support was probably from his mother's kindred in the lands around Liège. After Amblève, he seems to have won the backing of the influential Willibrord, founder of the Abbey of Echternach. The abbey had been built on land donated by Plectrude's mother Irmina of Oeren, but most of Willibrord's missionary work had been carried out in Frisia. In joining Chilperic and Raganfrid, Radbod sacked Utrecht, burning churches and killing many missionaries. Willibrord and his monks were forced to flee to Echternach. Gerberding suggests that Willibrord had decided that the chances of preserving his life's work were better with a successful field commander like Charles than with Plectrude in Cologne. Willibrord subsequently baptized Charles's son Pepin. Gerberding suggests a likely date of Easter 716. Charles also received support from Bishop Pepo of Verdun.
Charles took time to rally more men and prepare. By the following spring, he had attracted enough support to invade Neustria. Charles sent an envoy who proposed a cessation of hostilities if Chilperic would recognize his rights as mayor of the palace in Austrasia. The refusal was not unexpected but served to impress upon Charles's forces the unreasonableness of the Neustrians. They met near Cambrai at the Battle of Vinchy on 21 March 717. The victorious Charles pursued the fleeing king and mayor to Paris, but as he was not yet prepared to hold the city, he turned back to deal with Plectrude and Cologne. He took the city and dispersed her adherents. Plectrude was allowed to retire to a convent. Theudoald lived to 741 under Charles's protection.
Upon this success, Charles proclaimed Chlothar IV king in Austrasia in opposition to Chilperic and deposed Rigobert, archbishop of Reims, replacing him with Milo, a lifelong supporter. In 718 Chilperic responded to Charles's ascendancy by making an alliance with Odo the Great, the duke of Aquitaine, who had become independent during the civil war in 715. The alliance was defeated by Charles at the Battle of Soissons. Chilperic fled with Odo south of the Loire, and Raganfrid fled to Angers. Odo then surrendered Chilperic in exchange for Charles recognizing his dukedom. Charles recognized Chilperic as king of the Franks in return for legitimate royal affirmation of his own mayoralty over all the kingdoms.
Between 718 and 732, Charles secured his power through a series of victories. Having unified Francia under his banner, Charles was determined to punish the Saxons who had invaded Austrasia. In late 718 he laid waste their country to the banks of the Weser, the Lippe, and the Ruhr, securing the northern Frankish border.
When Radbod died in 719, Charles seized West Frisia without any great resistance on the part of the Frisians, who had been subjected to the Franks but had rebelled upon the death of Pippin. When Chilperic II died in 721, Charles appointed as his successor the son of Dagobert III, Theuderic IV, who occupied the throne from 721 to 737. Charles was now appointing the kings whom he supposedly served (rois fainéants). By the end of his reign, he did not appoint any at all. At this time, Charles again marched against the Saxons. Then the Neustrians rebelled under Raganfrid, who had left the County of Anjou. They were easily defeated in 724, but Raganfrid gave up his sons as hostages in turn for keeping his county. This ended the civil wars of Charles's reign.