The Quadi were a smaller Germanic tribe, about which little is definitively known. We only know the Germanic tribe the Romans 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, whose name simply means the "men of the borderlands" living on the frontiers of Germany, where it was bordered by the River Danube, south of which lay Roman territory.

Perhaps originating north of the River Main, the Quadi and Marcomanni migrated into what is now Moravia, western Slovakia and Lower Austria where they displaced Celtic cultures and were first noticed by Romans in 8–6 BC, briefly documented by Tacitus in his Germania. A further Marcomannic confederation that included the Quadi fought the future emperor Tiberius in 6 AD.

There may be an earlier reference to the Quadi in the Geography of Strabo (7.1.3). In a parenthetical expression, often removed from the main text, he mentions a branch of the Suevi called the Koldouoi, transliterated to Latin Coldui (Strabo wrote in Greek). Part of their range is Bohemia, the domain of Maroboduus. The emendment of Coldui to Coadui (Quadi) is generally considered correct.