The 13th century poet, Kavi Kabila, while commenting broadly on the Ramayana and on Rama's killing of Raavan with the active support of the latter's estranged younger brother Vibhisan - upon whom Raavan had vowed black vengeance and on the killing of Bali (again by Rama) with the ready contrivance of his younger, disgruntled and banished, sibling Sugreev, has succinctly expressed this in a couplet: