The Marcomanni were a Germanic tribe, probably related to the Buri
Buri (Germanic tribe)
The Buri were a Germanic tribe mentioned in the Germania of Tacitus, where they initially "close the back" of the Marcomanni and Quadi of Bohemia and Moravia. It is said that their speech and customs were like those of the Suebi...

, Suebi
The Suebi or Suevi were a group of Germanic peoples who were first mentioned by Julius Caesar in connection with Ariovistus' campaign, c...

 or Suevi.
Scholars believe their name derives possibly from Proto-Germanic forms of "march
A march or mark refers to a border region similar to a frontier, such as the Welsh Marches, the borderland between England and Wales. During the Frankish Carolingian Dynasty, the word spread throughout Europe....

" ("frontier, border") and "men".

The Marcomanni settled in the Main River valley soon after 100 BC. To escape Roman aggression in 9 BC they migrated east to Bohemia, where their king Maroboduus
Maroboduus , was king of the Marcomanni. The name "Maroboduus" can be broken down into two Celtic elements, māro- meaning "great" , and bodwos meaning "raven"...

 established a powerful kingdom that Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

 perceived as a threat to Rome
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....