## **1\. Introduction and fundamental reorientation of the discourse**

The postglacial development of the Baltic Sea, particularly the transition from a lacustrine to a brackish-marine system, represents one of the most significant paleogeographic, paleoclimatological, and paleoecological transformations of the entire Holocene.1 The central chronostratigraphic event of this far-reaching development is the so-called Littorina Transgression. Triggered by the eustatic sea-level rise, which was primarily caused by the final melting of the large continental ice sheets of the Pleistocene (especially the Laurentide Ice Sheet), marine water masses flooded the topographic barriers of the Danish straits and penetrated deep into the hitherto largely freshwater-dominated Baltic Sea basin.1 This complex, multi-phase process profoundly changed not only the entire hydrographic system of the region but also completely reshaped the coastlines of Northern and Central Europe.1 

In the classical geoscientific paradigm, the course of this transgression is understood as a gradual process dominated by climatic and eustatic factors, which culminated in the early to middle Holocene – roughly between 8,500 and 4,000 years before present (cal. BP).8 After reaching the transgression and salinity maximum, according to the established doctrine, the system transitioned into a phase of relative stability or slight regression, driven primarily by the isostatic rebound of the Scandinavian landmass interacting with a decelerating eustatic rise.9  
Recent interdisciplinary research, specifically the detailed geodynamic, geochemical, and cartometric re-evaluation of the geographic data of *Germania Magna* transmitted by Claudius Ptolemy (c. 150 AD), now fundamentally challenges this paradigm of calm, fading coastal dynamics in the Late Holocene.\[13, 13\] The modeling of the ancient geographic coordinates based on a strictly affine transformation suggests that the coastline of the *Oceanus Germanicus* (the southern North and Baltic Sea) in late antiquity was located about 120 kilometers further south than it is today.\[13, 13\]  

If this interdisciplinary hypothesis proves true, it forces the scientific community to massively revise the current understanding of the exact course, duration, and above all, the definitive end of the Littorina Transgression. It implies that the transgression did not transition into a static Post-Littorina stage in the middle Holocene but continued continuously over millennia into the Roman Imperial Period, and was only abruptly ended in the 6th century AD by a catastrophic, primarily tectonically driven event.\[13, 13\] This report analyzes the empirical evidence of the classical model, systematically contrasts it with the new geodynamic findings, and evaluates the far-reaching implications for Quaternary geology, geoarchaeology, and the understanding of postglacial geodynamics in Europe.

The reconstruction of the ancient geography of Germania and neighboring Sarmatia has always resembled a complex puzzle, in which the written records of classical antiquity are often difficult to reconcile with the physical realities of modern topography. One of the most fascinating questions in this context concerns the identity of the island of Scandia, which Claudius Ptolemy describes in his Geographike Hyphegesis as a significant island east of the Cimbrian Peninsula.¹ Parallel to this exists the deeply rooted legend of Vineta, a magnificent city sunk in the sea along the Baltic coast, whose historical core is most commonly assumed to lie in the region of Wollin or Usedom.² ³ The scholarly challenge is to examine whether Scandia and Vineta refer to the same geographical feature, merely named differently from distinct ethnic perspectives. A central hypothesis here is that the Sarmatian or Scythian peoples of the east called the island Vineta (or a precursor thereof) because of the Veneti who lived there, while the local population of western Germania Magna used the name Scandia.⁴

The scholarly engagement with Claudius Ptolemy’s Geographike Hyphegesis, particularly regarding the territory of Germania Magna, has faced a fundamental paradox for centuries. While the mathematical coordinates in Ptolemy’s atlas suggest an apparently precise mapping, the described landmarks, river courses, and settlement points can often only be reconciled with the present-day topography of Central Europe through considerable distortion. Traditional research has usually resolved this problem by assuming measurement errors on the part of the ancient sources or by allowing generous interpretive latitude in the identification of hydronyms and toponyms. The researcher Sven Mildner, however, takes a radically different approach in his work: he postulates that the Ptolemaic data are not primarily erroneous, but that the modern interpretation rests on a fundamental misconception about the stability of the European landscape and an incorrect cartographic projection.¹

At the heart of Mildner’s thesis is the re-identification of the Vistula Fluvius. While established historiography invariably equates the Vistula with the present-day Vistula (Weichsel) in Poland, Mildner’s computer-assisted distortion analyses of medieval maps indicate that the ancient Vistula actually describes a river system in what is now eastern Germany, encompassing the Black Elster, the Spree, and parts of the Oder.¹ This westward shift of the central eastern boundary river of Germania Magna by several hundred kilometers has far-reaching consequences for the entire historical geography of Central Europe. It necessitates a re-evaluation of the settlement areas of Germanic tribes such as the Lugii, Burgundians, and Vandals, as well as an explanation of how such a prominent hydronym could “migrate” eastward in the transmitted record.²

The methodological foundation of this re-evaluation is the realization that geodynamic processes, climatic caesuras, and cartographic transmission errors interacted synergistically. The image of Germania Magna was fragmented in the 6th century AD by an unprecedented ecological and demographic catastrophe. The resulting settlement hiatus led to a break in the oral tradition of landscape designations.² When medieval cartographers such as Donnus Nicolaus Germanus began to reconstruct the ancient knowledge, they projected the Ptolemaic coordinates onto a changed physical world and thereby created the distortions that Mildner describes in his new interpretation.²

The study of Claudius Ptolemy’s Geographike Hyphegesis, written around 150 AD, represents one of the most complex tasks in historical geography. With over 6,300 recorded places and their coordinates, the work forms the fundamental framework for our understanding of the ancient world.¹ The scholarly challenge arises from the discrepancy between the ancient data and modern topography, which has historically often been attributed to faulty transmission or insufficient measurement accuracy. The plausibility analysis presented here addresses a radical paradigm shift: the identification of the ancient Vistula not with the Weichsel (Vistula) in Poland, but with the system of the Black Elster in present-day Lusatia, as postulated by Sven Mildner in his publication on Germania Magna.²

This approach is based on the realization that Ptolemy calculated with an Earth circumference of 180,000 stadia, which led to a systematic distortion of the coordinates.¹ Modern research, particularly projects at the Technical University of Berlin by Kleineberg, Marx, and Lelgemann, has shown that more precise localization of ancient settlements is possible through mathematical rectification and statistical analyses.⁴ Sven Mildner’s reinterpretation expands this geodetic framework by incorporating interdisciplinary parameters from geodynamics and archaeometallurgy to create a coherent landscape reconstruction of Germania Magna.³