Charlemagne led his Franks on campaigns of conquest in nearly every year of his reign. From this general pattern, however, the years 791–93 stand out in sharp relief. Even the strong stimulus of Count Theodoric's defeat by the Saxons in 793 and renewed Muslim incursions from Spain failed to evoke any response by the great king himself. The anomalous cluster of 792–94 events deviating from the established pattern include the natural disasters of an equine epidemic in autumn of 791 and a famine in 793. Politically, Pippin the Hunchback, Charlemagne's eldest son, rebelled in 792, and Duke Grimoald of Benevento defected to the Byzantines. Yet with all these emergencies urging vigorous action, Charlemagne spent 792–93 sitting motionless at Regensburg, an exceptionally prolonged residency there, building mobile bridges in the first year and working on a great (though ultimately unsuccessful) canal project in the second. Never before in his reign had this peripatetic and warlike King of the Franks appeared so passive. At the core of these difficulties was a lack of mobility as evidenced by the unusually long stay at Regensburg with no response to imminent military emergencies.

Modern historians have recognized that this atypical period required some explanation. Hofmann suggested that the famine of 793 prevented Charlemagne from moving away from the plentiful reserves at Regensburg. Karl Ferdinand Werner explained that itinerant kingship was more concerned with prosecuting military campaigns than with providing sustenance for the royal retinue so that Charlemagne's stay at Regensburg should be associated with the Avar campaign.