The Hittite language was a distinct member of the Anatolian branch of the Indo-European language family, and along with the closely related Luwian language, is the oldest historically attested Indo-European language, referred to by its speakers as "in the language of Nesa". The Hittites called their country the "Kingdom of Hattusa" (Hatti in Akkadian), a name received from the Hattians, an earlier people who inhabited the region until the beginning of the second millennium BC and spoke an unrelated language known as Hattic. The conventional name "Hittites" is due to their initial identification with the Biblical Hittites in 19th century archaeology.