Il controllo delle acque fluviali nell’Italia settentrionale (IV-VIII secolo): spunti di riflessione, tra fonti scritte e documentazione archeologica

One of the most recurrent topics in historiography regarding landscape transformations in Late Antiquity is related to flooding and loss of control over rivers, essentially attributed to two factors: 1/ the increase in rainfall and decrease in temperature, as part of the so-called Late Antique Little Ice Age (LALIA), on which paleoclimatological studies have focused in particular; 2/the loss of control over water courses, that took place in the Roman period, mainly related to depopulation that would have prevented the extensive maintenance works on the banks and canalisations. In this context, particularly with regard to northern Italy, which is the subject of this contribution, some passages of the Dialogi of Gregory the Great and Paul the Deacon (notably the famous mention of the diluvium in 589) are often evoked, recalling miraculous interventions of saints who stopped floods or diverted the rivers, thus saving cities and countryside. The paper aims to discuss and argue these perspectives, examining the context and the purposes of the cited texts, actually written with a moralisticeschatological intention, but also widening the glance to other types of sources, literary, juridical as well as the Corpus agrimensorum, from which it clearly appears that the theme of floods was already well present in the imperial age. The archaeological record is also examined, providing useful information to more precisely discuss the chronology and the real extent of the floods, showing a very diverse and complex reality.