Rhine to Toul, it is substantially true to say that the course of the Meuse and a part of that of the Moselle formed the border line between the two kingdoms. Thence the frontier ran to the Saône valley, and the limits thus fixed, although not lasting, had distinct influence later in the Middle Ages.
Hardly was the treaty of Meersen concluded, when the brother-kings of Gaul and Germany were confronted by deputies from the Pope and the Emperor, protesting, in the name of the latter, against the conduct of his uncles in thus robbing him of the inheritance which was his by right. Hincmar replied by endeavouring to justify his master, and by dwelling on the necessity of preserving peace in Lorraine; Charles, for his part, bestowed fair words and rich gifts on the Pope. As to Louis the German, he professed himself ready to make over what he had acquired of Lothar's lands to Louis II. These assurances, however, were not followed by any practical result, and Charles spent the latter part of the year in completing the subjection of the southern part of his newly-acquired dominions. Lyons was occupied without a struggle. Only Vienne, which was defended by Bertha, wife of Gerard of Roussillon, who was himself ensconced in a castle in the neighbourhood, made some resistance, surrendering, however, in the end (24 December 870). Charles was recalled to Francia by the rebellion of his son Carloman, who had forsaken his father's expedition in order to collect bands of partisans and ravage his kingdom. Louis the German was at the same time engaged in a struggle with his two sons who had risen against him. Charles confided the government of the Viennois and Provence to his brother-in-law Boso as duke, and turned homewards.
In the meanwhile, a report spread through Gaul and Germany that the Emperor Louis II had been taken prisoner and put to death by Adelchis, Prince of Benevento. In reality the latter had merely subjected his sovereign to a few days' captivity (August 871). But Louis the German and Charles the Bald had lost no time in shewing that each intended to appropriate for himself the inheritance left by the deceased; Louis by sending his son Charles the Fat beyond the Alps, in order to gather adherents, and Charles by setting out himself at the head of an army. However, he went no further than Besançon, when the two competitors were stopped by the news that the Emperor was still alive. But during the three following years we find both brothers bent on eventually securing the heritage of the king of Italy; Louis the German being supported, it would seen, by the Empress Engilberga, while Charles the Bald, who had rid himself of his rebellious son Carloman, whom he had succeeded in making prisoner and whose eyes he had put out, was trying to form a party among the Roman nobles and those surrounding the new Pope, John VIII, who in December 872 had taken the place of Hadrian. The death of Louis II at Brescia (12 August 875) led to an open struggle between the two rivals.
