Purushottam Nagesh Oak (2 March 1917 – 4 December 2007), commonly referred to as P.
N.
Oak, was a fringe Hinducentric historical negationist from India.
Among his prominent claims were that Christianity and Islam are both derivatives of Hinduism, Vatican City, Kaaba, Westminster Abbey and the Taj Mahal were once Hindu temples dedicated to Mahadeva and that the Papacy was originally a Vedic Priesthood; their reception in Indian popular culture have been noted by observers of contemporary Indian society.
He ran an 'Institute for Rewriting Indian History' in the 1980s which published a quarterly periodical called Itihas Patrika dedicated to fringe causes; he had also written numerous books, some of which have even lead to court cases in a bid to correct the mainstream history narrative.