population displacement, although there was an outmigration of Goths. Rather, more recent theories explain the collapse of the Chernyakhov culture in terms of a disruption of the hierarchical political structure that maintained it. John Mathews suggests that, despite its cultural homogeneity, a sense of ethnic distinction was kept between the disparate peoples. Some of the autochthonous elements persist, and become even more widespread, after the demise of the Gothic elite – a phenomenon associated with the rise and expansion of the early Slavs. Migration and diffusion theories Migration Whilst acknowledging the mixed origins of the Chernyakiv culture, Peter Heather suggests that the culture is ultimately a reflection of the Goths' domination of the Pontic area. He cites literary sources that attest that the Goths were the centre of political attention at this time. In particular, the culture's development corresponds well with Jordanes' tale of Gothic migration from Gothiscandza to Oium, under the leadership of Filimer. Moreover, he highlights that crucial external influences that catalysed Chernyakhov cultural development derived from the Wielbark culture. Originating in the mid-1st century, it spread from south of the Baltic Sea (from territory around later Pomerania) down the Vistula in the 2nd and 3rd centuries. Wielbark elements are prominent in the Chernyakhov zone, such as typical 'Germanic' pottery, brooch types and female costume, and, in particular, weaponless bi-ritual burials. Although cultures may spread without substantial population movements, Heather draws attention to a decrease in the number of settlements in the original Pomeranian Wielbark heartland as evidence of a significant population movement. Combined with Jordanes' account, Heather concludes that a movement of Goths (and other east Germanic groups such as Heruli and Gepids) "played a major role in the creation of the Cernjachove culture". He clarifies that this movement was not a single, royal-led, migration, but was rather accomplished by a series of small, sometimes mutually antagonistic groups. Diffusion However, Guy Halsall challenges some of Heather's conclusions. He sees no chronological development from the Wielbark to Chernyakhov culture, given that the latter stage of the Wielbark culture is synchronous with Chernyakhov, and the two regions have minimal territorial overlap. "Although it is often claimed that Cernjachov metalwork derives from Wielbark types, close examination reveals no more than a few types with general similarities to Wielbark types". Michael Kulikowski also challenges the Wielbark connection, highlighting that the greatest reason for Wielbark-Chernyakhov connection derives from a "negative characteristic" (i.e.,