It is a commonplace that the expansion of the Carolingian empire slowed down rapidly after 800 and came to a halt under Louis the Pious. It is also well known that both Charles in the last years of his reign and Louis the Pious experienced difficulty in raising armies. This paper will re-examine these two well-established facts and suggest some explanations, continuing lines of argument already developed in a previous article. It may be as well to begin by chronicling the end of expansion. The crushing of the Avars in the 790s was the last really large aggressive military operation conducted by the Carolingians; the final incorporation of the Saxons into the Frankish empire, marked by the peace of Salz in 803 and the de-Saxonization of Transalbingia in the following year, brought to an end what Einhard rightly described as the most serious of all the wars fought by the Franks. In the period between 802/3 and the crisis of 830 there was intermittent warfare on a number of fronts: in the south-west against the Muslims of Spain and the Basques; in the north-west against the Bretons; in the north-east against the Danes and their Slav allies; in the south-east against the Serbs and the Bulgars; and in Italy against the Byzantines and Beneventans. In addition there were invasion scares in the 800s on the north French coast, real invasions in southern Italy and Frisia, and skirmishes in the Mediterranean islands.