Carloman's reign proved short and troublesome. The brothers shared possession of Aquitaine, which broke into rebellion upon the death of Pepin the Short; when Charlemagne campaigned to put down the revolt, Carloman led his own army to assist. The two quarreled at Moncontour, near Poitiers, and Carloman withdrew. This, it had been suggested, was an attempt to undermine Charlemagne's power, since the rebellion threatened Charlemagne's rule. Charlemagne crushed the rebels, whilst Carloman's behaviour had damaged his own standing amongst the Franks. Relations between the two then degenerated further, requiring the mediation of their mother, Bertrada, who appears to have favoured Charlemagne, with whom she would live out her widowhood.