He was not able to follow up his advantage immediately, for the possibility of his defeat by the Saracens had emboldened his enemies at home and abroad, to rise against his authority. The Frisians, under Poppo, their new Duke, made another invasion; the Saxons followed their example; the Burgundians attempted a rebellion, and the sons of Duke Eudo of Aquitaine, imitating the example of their ancestors, the Merovingian kings, began to quarrel about the succession. While Karl Martel (as we must now call him) was engaged in suppressing all these troubles, the Saracens, with the aid of the malcontent Burgundians, occupied all the territory bordering the Mediterranean, on both sides of the Rhone. He was not free to march against them until 737, when he made his appearance with a large army, retook Avignon, Arles and Nismes, and left them in possession only of Narbonne, which was too strongly fortified to be taken by assault. Karl Martel was recalled to the opposite end of the kingdom by a fresh invasion of the Saxons. When this had been repelled, and the northern frontier in Germany strengthened against the hostile race, the Burgundian nobles in Provence sought a fresh alliance with the Saracens, and compelled him to return instantly from the Weser to the shores of the Mediterranean. He suppressed the rebellion, but was obliged to leave the Saracens in possession of a part of the coast, between the Rhone and the Pyrenees. During his stay in the south of France, the Pope, Gregory II., entreated him to come to Italy and relieve Rome from the oppression of Luitprand, king of the Longobards. He did not accept the invitation, but it appears that, as mediator, he assisted in concluding a treaty between the Pope and king, which arranged their differences for a time. [Sidenote: 741.] Worn out by his life of marches and battles, Karl Martel became prematurely old, and died in 741, at the age of fifty, after a reign of twenty-seven years. He inherited the activity, the ability, and also the easy principles of his father, Pippin of Heristall. But his authority was greatly increased, and he used it to lessen the remnant of their original freedom which the people still retained. The free Germanic Franks were accustomed to meet every year, in the month of March (as on the _Champ de Mars_, or March-field, at Paris), and discuss all national matters. In Chlodwig's time the royal dependents were added to the free citizens and allowed an equal voice, which threw an additional power into the hands of the monarch. Karl Martel convoked the national assembly, declared war or made peace, without asking the people's consent; while, by adding the priesthood and the nobles, with their dependents, to the number of those entitled to vote, he broke down the ancient power of the state and laid the foundation of a more absolute system.