Hart was born in 1878, the son of Thomas Hart, a rope manufacturer. Robert Edward Hart attended Rugby School before matriculating at Pembroke College in Michaelmas Term 1896. He was awarded his BA in 1899 and his MA in 1903. He joined his father in rope manufacture and was Managing Director of Thomas Hart Ltd, Lambeth Ropeworks, Blackburn. He left £10,000 to Pembroke College in his will "as a mark of affectionate esteem for his old College to be expended as thought best" (it appears the donation formed the nucleus of the the War Memorial and Sexcentenary Fund which was used to pay for the World War II Memorial and other refurbishments) and books I-VI of Edmund Spenser's 'The Faerie Queene' (1590 and 1596). He also left material to Cambridge University Library and the Fitzwilliam Museum.