The proximity of dangerous barbarian tribes (Quadi, Marcomanni) necessitated the presence of a large number of troops (seven legions in later times), and numerous fortresses were built on the bank of the Danube.
The Marcomanni disappeared from history during the 4th century, being probably merged in the Baiouarii, the later Bavarians.
Most likely they were descendants of the Marcomanni, Quadi and Narisci, tribes of the Suevic or Swabian race, with possibly a small intermixture of Gothic or Celtic elements.
The hero's later years were spent in fighting against Marbod, prince of the Marcomanni, and in disputes with his own people occasioned probably by his desire to found a powerful kingdom.
The Boii were expelled from their territories inBohemia by the Marcomanni in the time of Augustus, and the Helvetii are also recorded to have occupied formerly lands east of the Rhine, in what is now Baden and Wurttemberg.