Nkuba ('Lightning / Thunderbolt'), titled Umwami wo Hejuru, 'the King of the Sky,' is the celestial sovereign at the head of the Ibimanuka ('those fallen from the heavens') in the Rwandan dynastic origin myth recorded by d'Hertefelt & Coupez and in Kagame's dynastic poem Ubucurabwenge. In the royal genealogy 'Nkuba (the thunder) begat Kigwa (the fallen one), who begat Muntu,' and the line continues through the celestial ancestors down to the founder-king Gihanga, so that Nkuba is the apical sky-father of the Rwandan kings. The sky he rules is the 'point of departure' from which the royal line descends to earth; above him stands the transcendent creator Imana, who is the principal agent of that engendering. Nkuba is distinct from (though comparable to) the Nyanga lightning-god of the same name in neighboring Great Lakes Bantu traditions.