Factual and detailed knowledge about the early history of the Germanic tribes is rare. Researchers have to be content with the recordings of the tribes' affairs with the Romans, linguistic conclusions, archaeological discoveries and the rather new yet auspicious results of archaeogenetic study. In the mid-1st century BC, Julius Caesar erected the first known bridges across the Rhine during his campaign in Gaul and led a military contingent across and into the territories of the local Germanic tribes. After several days and having made no contact with Germanic troops (who had retreated inland) Caesar returned to the west of the river. The Suebi tribe under chieftain Ariovistus, had around 60 BC conquered lands of the Gallic Aedui tribe to the west of the Rhine. Consequent plans to populate the region with Germanic settlers from the east were vehemently opposed by Caesar, who had already launched his ambitious campaign to subjugate all Gaul. Julius Caesar confronts and beats the Suebi forces in 58 BC in the Battle of Vosges and forces Ariovist to retreat across the Rhine.