suggest that Dacian groups settled among the local Celts in the region of the rivers Bodrog, Hron and Nitra. The spread of the "Púchov culture", associated with the Celtic Cotini, shows that the bearers of that culture started a northward expansion during the same period. The Romans and the Germanic tribes launched their first invasions against the territories along the Middle Danube in the last decade of the . Roman legions crossed the Danube near Bratislava under the command of Tiberius to fight against the Germanic Quadi in , but the local tribes' rebellion in Pannonia forced the Romans to return. Taking advantage of internal strifes, the Romans settled a group of Quadi in the lowlands along the Danube between the rivers Morava and Váh in 21, making Vannius their king. The Germans lived in rectangular houses, rather than square ones, and cremated their dead, placing the ashes in an urn. Although the Danube formed the frontier between the Roman Empire and the "Barbaricum", the Romans built small outposts along the left bank of the Danube, for instance, at Iža and Devín. During the same period, the Germanic tribes were expanding to the north along the rivers Hron, Ipeľ and Nitra. Roman troops crossed the Danube several times during the Marcomannic Wars between 160 and 180. Emperor Marcus Aurelius accomplished the first chapter of his Meditations during a campaign against the Quadi in the region of the Hron River in 172. The "Miracle of the Rain"a storm which saved an exhausted Roman armyoccurred in the land north of the Danube in 173; Christian authors attributed it to a Christian soldier's prayer. Roman troops crossed the Danube for the last time in 374, during Emperor Valentinian I's campaign against the Quadi who had allied with the Sarmatians and invaded the Roman province of Pannonia. Medieval history New migrations In the 4th century AD, the Roman Empire could no longer resist the attacks by the neighboring peoples. The empire's frontier started to collapse along the Danube in the 370s. The development of the Hunnic Empire in the Eurasian Steppes forced large groups of Germanic peoples, including the Quadi and the Vandals, to leave their homelands by the Middle Danube and along the upper course of the river Tisza in the early . Their lands were occupied by the Heruli, Sciri, Rugii and other Germanic peoples. However, the Carpathian Basin was dominated by