Complex sentence: The Bantu expansion reached the area by the 1st millennium AD, and the borders of the modern state comprise the crossroads of the Nilo-Saharan, the Afro-Asiatic and the Bantu linguistic areals of Africa, making Kenya a truly multi-ethnic state.
Split into simpler sentences: The Bantu expansion reached the area by the 1st millennium AD. With the borders of the modern state at the crossroads of the Bantu, Nilo-Saharan and Afro-Asiatic ethno-linguistic areals of Africa, Kenya is a truly multi-ethnic state.