Various research articles published confirm the fact that Vijayanagara kings belonged to Kuruba community. The article published by B.A. Salatore in 1936 through the "Vijayanagara Sexcentenary Association" deals with this topic in detail. The "Journal of Andhra Historical Research Society" published an article by B.V.Sreenivasa Rao between 1950-1960 (Volume 25) which points that Harihara and Bukka were Telugu speaking Kurubas The Great king Krishnadeva Raya himself mentions that he belongs to the Kuruba/Golla clan in his Telugu literary work "Amuktamalayada". If any one has any doubts then they are welcome to check the papers published by both Indian and Foreign authors after doing research about the origin of Vijayanagara. I am posting the link below and these articles can be obtained from any Kannada or Telugu university in India.
The great Kurubas halted the Muslim invasion of South India and helped preserve the Hindu Culture. In the process were feared by the Muslims and as areason were discriminated by the Nizam rulers of Hyderabad and were opressed for a long period. The rebillion by Sangolli Rayanna and the Holkars of Indore brought Kurubas in direct confrontaion with the British who feared them most and were prevented from using weapons and were supressed for their fight against the British. This could be the main reason why many Kurubas with a glorious history are lagging behind in the modern times, and lack the knowledge of their rich and proud past.