The Suebi, also known as the Suevi or Suavi, was an alliance of Germanic tribes sharing common language and gods. During the 1st century BC, King Ariovistus was rewarded with new lands beyond Germania across the Rhine River by the Sequani in exchange for their assistance, along with the Arverni, in the war with the Roman-allied Aedui tribe. The Suebi settled across the Rhine in ever-greater numbers, and the tribe was forced back across the Rhine by Julius Caesar's Roman army in the Battle of Vosges in 58 BC. The mobile Suebi tribes would become a threat to the Roman Empire on its Rhine and Danube frontiers after migrating from the Baltic Sea and the Elbe River, and the southwestern German region of Swabia took its name from the Suebi tribe. Towards the end of the empire, the Alemanni tribe of the Suebi occupied Alsace in eastern France, and other Suebi made it as far as Gaul and Gallaecia in northwestern Spain and northern Portugal. From 409 to 585, a Suebic kingdom existed in Spain, and it was later conquered by the Visigoths.