Ariovistus was a leader of the Suebi and other allied Germanic peoples in the second quarter of the 1st century BC. He and his followers took part in a war in Gaul, assisting the Arverni and Sequani to defeat their rivals the Aedui, after which they settled in large numbers in conquered Gallic territory in the Alsace region. They were defeated, however, in the Battle of Vosges and driven back over the Rhine in 58 BC by Julius Caesar.
Ariovistus and the events he was part of are known from Caesar's Commentarii de Bello Gallico. Caesar, as a participant in the events, is a primary source, although as his Commentaries were in part political propaganda they may be suspected of being self-serving. Later historians, notably Dio Cassius, are suspicious of his motives.
Ariovistus was a native of the Suebi. He spoke Gaulish fluently. He had two wives, one of whom he had brought from home. The second, who was the sister of King Vocion of Noricum, he acquired in an arranged political marriage.