Luwian-speaking peoples came into Anatolia in the third millennium B.C., about the same time as the Hittites. They settled mainly in the south and west and founded several kingdoms—the most important being Kizzuwatna in the southeast (roughly equivalent to Cilicia in later years) and Arzawa in the west (the region surrounding Ephesus). The Luwians were at different times allies, rivals and vassals of the Hittites. Since their languages were about as closely related as modern Dutch and German, there was a good deal of cultural exchange between the two peoples, especially between Kizzuwatna and Hatti (as the Hittites called their territory in central Anatolia).