"Alboenus rex Langobardorum cum omni exercitu relinquens [...] Pannoniam [...] in fara". Analysing population and migration dynamics of the Lombard Landnahme of Italy in 568 CE with agent-based modelling

Abstract of thesis, which this dataset belongs to: The study of the Lombard gens and their migration between the 5th and 8th centuries CE remains a focal point of early medieval research, especially concerning its role in the socio-political restructuring of Europe following the migration period. The Lombard Landnahme of Italy in 568 CE hereby represents a main area of importance due to its centuries-long effect on italian history. Since this impact directly relates to group size and demographic structure of the incoming gens, the same have been discussed for decades. Due to the scarcity and often mythologised nature of contemporary written sources, such fundamental palaeodemographic examinations remain largely hypothetical. To address this research gap, this thesis applies an interdisciplinary approach by combining traditional historical research with methods of palaeodemography and agent-based modeling (ABM). Based on contemporary written sources and a sample of 20 Lombard-era burial grounds (comprising 3,252 individuals), size and migration dynamics of the group involved in the process of the Lombard Landnahme (c. 500 – 700 CE) will be estimated with these methods. Special focus will be put on determining whether the Lombard group migrated as a whole or in smaller, independently organised groups (farae); a matter which has been discussed for decades. Firstly, palaeodemography formulas are applied to the compiled skeletal series for the estimation of crude population sizes. Population growth rates and other relevant demographic information is also determined from the sample. After accounting for typical archaeological bias, which significantly affect the computed population sizes, the values serve as base input for two different agent-based models (MOD1 and MOD2). MOD1 simulates the complete, collective migration of the whole Lombard population, while MOD2 explores a farae-led migration dynamic. Results from palaeodemographic calculations indicate a very small Lombard population, corresponding to historical sources. While the appliction of correction factors elevates these population numbers, causing them to comply to commonly assumed group sizes, the danger of circular reasoning is high. Palaeodemographic correction factors should only be applied if affecting circumstances are well known and smaller, local population studies are performed. While both ABM results corroborate low population numbers, a migration process in smaller units (farae) exhibits higher demographic resilience and more accurately reflects the archaeologic record. The models were also able to demonstrate the complex socio-political circumstances of the period and their influence on the Lombard Landnahme with the choice of migration routes taken by agents. This repository includes the generated raw data, which was produced during the agent-based modelling process (all files with "BehaviorSpace") or palaeodemographic calculations (PalaeodemographicData) and a comprehensive list of burial grounds (BurialGroundsLiterature), which was produced during the initial research phase for determination of relevant sample sites. Additionally, the model code for MOD1 and MOD2 (NetLogo) can be found here as well as all input and output data for the calculation of the population growth rates with the method developed by Galeta & Pankowská (2023). For a detailed description of all files and their purpose see README file.