Wikipedia
Aesti
The Aesti (also Aestii or Aests) were an ancient people first described by the Roman historian Tacitus in his treatise Germania (circa 98 CE). According to Tacitus, Aestui, the land of the Aesti, was located somewhere east of the Suiones (Swedes) and west of the Sitones (possibly the Kvens), on the Suebian (Baltic) Sea. This and other evidence suggests that Aestui was in or near the present-day Russian enclave of Kaliningrad Oblast (previously East Prussia).
Despite the phonological similarity between Aestui and the modern ethnonyms of Estonia, especially in popular etymologies, the two geographical areas are not contiguous and there are few, if any, direct historical links between them.