 Originally, Iapydes existed at least from the 9th century BC, and Celtic influence reached the region in the 4th century BC when Iapydes enter a decline.Archeological evidence of typical Celtic culture is documented only in the marginal contact zone of the Iapydes and the Celtic "Taurisci" along the Kupa river valley (now the Slovenian-Croatian border).Elsewhere, and especially in the main Iapydic area of the Lika highlands in Croatia, definite Celtic artifacts are scarce and explicable merely by commercial exchanges.