Born on 21 October 1887, Shri Krishna Singh was the son of Harihar Singh of village Maur, P.S. Barbigha in Monghyr district. He passed Matric with first division in 1906 from the Monghyr District High English School. When he was a student of B.A. in Patna College, he went to Arrah in 1910 and he attended the fifth session of the “Bihari Students’ Conference” which was presided over by Sachchidanand Sinha, the eminent Buxarite and the pre-dominant leader of the separation movement of Bihar from the Fort-William presidency. Subsequent to obtaining the degree of M.A. in History in 1913 and did B.L. in 1914. He joined the District Court in Monghyr in 1915. Young Dr. Shri Krishna Singh was highly influenced by the political thinking of Lokmanya Tilak (1856-1920) and Arvind Ghosh. He actively participated in the movement of the Home Rule League as the prominent leader of Monghyr. He jumped into the vortex of the Non-Cooperation movement. He actively participated in the historic Civil Disobedience Movement. He took part in Individual Satyagraha Movement and the Quit India Movement and was arrested many times.
In the first and second general elections held in 1952 and in 1957 he was elected as M.L.A. from Kharagpur and Sheikhpura constituencies respectively and he headed the council of ministers in Bihar till his demise on 31 January 1961.