Which ruler of Kanpur called himself 'Peshwa'?

Nana Saheb, the adopted son of the last Peshwa Bajirao II, called himself 'Peshwa' during the Revolt of 1857. After the British refused to continue the pension granted to Bajirao II to Nana Saheb following his adoptive father's death, Nana Saheb became a leading figure of the 1857 revolt in Kanpur. He proclaimed himself the Peshwa and led the rebellion against the British in that region.