 The cause of Jaziga's increasing incursions into the Roman provinces of Pannonia and Moesia was probably not only a propensity for war and plunder (and later German pressure) but also partly limited living space and overcrowding.They were probable descendants of the Roxolani, who had migrated from Dacia to Banat.In 331, the Thervingi pushed west and south-west into the territory of the Arcaragantes.