He was the son of king Mwambutsa I Mbariza and Msabiyije, a wife from the influential Bashoka Tutsi clan.
[1] The early years of his reign began with a regency, which was common in Burundian royal history.
[1] Ntare's inherited kingdom was approximately half the size of the present-day Burundi.
[1] Eventually, around 1840, Ntare conquered the Buyogoma with the support of his son Rwasha.
He achieved the greatest expansion in the history of Burundi, doubling the territory.