After Sitobu founded the Dagbon Kingdom the kingship became known as Ya Naa, literally meaning King of strength (power). After the death of Sitobu he was succeeded by his son Naa Nyagse who spread the Kingdom of Dagbon in all four directions. Upon ascension to the skins of Yani, Naa Nyagse made war on the Dagbon Sablisi (Black Dagbamba) and founded YANI DABARI as the new seat (capital) of the Kingdom. On his way Naa Nyagse killed the TENDANA of Disega and then of Piugu and appointed his son Zakpabo as chief of Piugu. He then proceeded to Diare, Depale, Sena, Dalon, Tibun, Lunbuna, Vogu, Gbulun, Kumbungu, and Zugu, all in today’s Western Dagbon. The Tendamba (plural of Tendana) were killed and he appointed his sons Sheno, Danaa, Lareyogu, Kpalaga, Tuntie, Suzable, Legu, Binbien, and Waa respectively as chiefs of the conquered villages.
The success of Naa Nyagse is attributed primarily to a well structured military organization and a cavalry division that overwhelmed their opponents. The Dagbon Kingdom was surrounded by peoples of the African savannah, who lacked a sophisticated political or military organization and therefore fell easy prey to the “mounted warriors”. The cavalry were very instrumental in the spread of the Dagbon Kingdom. They could travel long distances across the flat open countryside of the north taking villages and establishing authority by appointing chiefdoms and chiefs in the conquered villages.
Naa Nyagse and subsequent kings of Dagbon, after conquering new villages, established themselves as rulers of the people. They appointed chiefs to preserve order and hardly influenced the way of life of the indigenes. The new rulers married from the conquered thus successfully assimilating the new villages into the Dagbon Empire.
At Zangbalun Naa Nyagse appointed his uncle, Burzambo, chief and at Didoge he appointed one of his followers, Bolega, as chief. Naa Nyagse continued on his conquest taking Kunkon, Zakole, and Nane. He installed his sons Tulibi, Bimbaliga, and Koledgenle as chiefs. At Karaga his uncle, brother of Sitobu became Karaga Naa while other uncles, Biyunkomba and Bogyelgu, were appointed to the chiefdoms of Mion and Sunson, respectively.
After the conquest in Western Dagbon, Naa Nyagse crossed the Oti River into Eastern Dagbon were he conquered Zabzugu installing his son Yalem chief and then proceeded to Nakpali and enskinned Yembageya. Next came Salenkogu, where his grandson, Nguhuriba was appointed chief and Tagnemo, went to another grandson, Kabiun.
Naa Nyagse then returned to Yogu and killed the Tendana of Namogu. It was while at Yogu that Naa Nyagse built Yani Dabari where he died in 1432.