About this time the Avars, coming from Hungary, had invaded Thuringia, and were inciting the people to rebellion against the Franks. Sigbert immediately marched against them, drove them back, and established his authority over the Thuringians. On returning home he found that his brother Chilperic had taken possession of his capital and many smaller towns. Chilperic was forced to retreat, lost his own kingdom in turn, and only received it again through the generosity of Sigbert,--the first and only instance of such a virtue in the Merovingian line of kings. Sigbert seems to have inherited the abilities, without the vices, of his grandfather Chlodwig. When the Avars made a second invasion into Germany, he was not only defeated but taken prisoner by them. Nevertheless, he immediately acquired such influence over their Khan, or chieftain, that he persuaded the latter to set him free, to make a treaty of peace and friendship, and to return with his Avars to Hungary. In the year 568 Charibert died in Paris, leaving no heirs. A new strife instantly broke out among the three remaining brothers; but it was for a time suspended, owing to the approach of a common danger. The Longobards, now masters of Northern Italy, crossed the Alps and began to overrun Switzerland, which the Franks possessed, through their victories over the Burgundians and the Alemanni. Sigbert and Guntram united their forces, and repelled the invasion with much slaughter. Then broke out in France a series of family wars, darker and bloodier than any which had gone before. The strife between the sons of Clotar and their children and grandchildren desolated France for forty years, and became all the more terrible because the women of the family entered into it with the men. All these Christian kings, like their father, were polygamists: each had several wives; yet they are described by the priestly chroniclers of their times as men who went about doing good, and whose lives were "acceptable to God"! Sigbert was the only exception: he had but one wife, Brunhilde, the daughter of a king of the Visigoths, a stately, handsome, intelligent woman, but proud and ambitious. [Sidenote: 570. FAMILY WARS IN FRANCE.]