The Chatti (also Chatthi or Catti) were an ancient Germanic tribe whose homeland was near the upper Weser (Visurgis), whose name might mean "pursuers". They lived in central and northern Hesse and southern Lower Saxony, along the upper reaches of that river and in the valleys and mountains of the Eder and Fulda regions, a district approximately corresponding to Hesse-Kassel, though probably somewhat more extensive. They settled within the region in the first century BC. According to Tacitus, the Batavians and Cananefates of his time, tribes living within the Roman Empire, were descended from part of the Chatti, who left their homeland after an internal quarrel drove them out, to take up new lands at the mouth of the Rhine.
The extremely large timescale of Prehistoric Europe left stone tools and weapons dating from the Paleolithic to the Iron Age that were chronologically ordered and dated in the nineteenth and twentieth centuries. Tribes such as the Chatti, Cimbri, and Langobardi have not been well distinguished until relatively recently.
While Julius Caesar (100–44 BC) was well informed about the regions and tribes on the eastern banks of the Rhine, he never mentioned the Chatti by name. He did make note of the Suebi though, and suggested that they had previously driven out the Celts to the south of the region corresponding to modern north Hesse in the prior centuries BC (cfr. the early medieval Hessengau). Pliny the Elder, in his Natural History (written 77–79 AD) grouped the Chatti and Suebi together with the Hermunduri and the Cherusci, calling this group the Hermiones, which is a nation of Germanic tribes mentioned by Tacitus as living in inland Germany. Some commentators believe that Caesar's Suebi were possibly the later Chatti, a branch of the Suebian movement of people who had become more clearly identifiable. If not, then the Chatti may represent a successful resistance to the Suevi, as opposed to the Tencteri, Usipetes, and Ubii who all were forced from homelands in the same region by the Suebic incursions.