The Quadi were a smaller Germanic tribe, about which little is definitively known. We only know the Germanic tribe the Romans

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 called the 'Quadi' through reports of the Romans themselves. No pottery style or other remains of material culture serve to distinguish Quadi encampments from those of closely related groups.
In the 1st century BC, according to Roman written sources, the Quadi were migrating alongside the more numerous Marcomanni

Marcomanni

The Marcomanni were a Germanic tribe, probably related to the Buri, Suebi or Suevi.-Origin:Scholars believe their name derives possibly from Proto-Germanic forms of "march" and "men"....

, whose name simply means the "men of the borderlands" living on the frontiers of Germany, where it was bordered by the River Danube

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

, south of which lay Roman territory.

Perhaps originating north of the River Main, the Quadi and Marcomanni migrated into what is now Moravia

Moravia

Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...

, western Slovakia

Slovakia

The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

 and Lower Austria

Lower Austria

Lower Austria is the northeasternmost state of the nine states in Austria. The capital of Lower Austria since 1986 is Sankt Pölten, the most recently designated capital town in Austria. The capital of Lower Austria had formerly been Vienna, even though Vienna is not officially part of Lower Austria...

 where they displaced Celt

Celt

The Celts were a diverse group of tribal societies in Iron Age and Roman-era Europe who spoke Celtic languages.The earliest archaeological culture commonly accepted as Celtic, or rather Proto-Celtic, was the central European Hallstatt culture , named for the rich grave finds in Hallstatt, Austria....

ic cultures and were first noticed by Romans in 8–6 BC, briefly documented by Tacitus

Tacitus

Publius Cornelius Tacitus was a senator and a historian of the Roman Empire. The surviving portions of his two major works—the Annals and the Histories—examine the reigns of the Roman Emperors Tiberius, Claudius, Nero and those who reigned in the Year of the Four Emperors...

 in his Germania

Germania (book)

The Germania , written by Gaius Cornelius Tacitus around 98, is an ethnographic work on the Germanic tribes outside the Roman Empire.-Contents:...

.