Bajirao Mastani Is a celebration of magnificent obsession - Bajiro's obsession with his beloved Mastani, and director Sanjay Leela Bhansali's Obsession with the 17th century Peshwa and his doomed love story. Sanjay has nurtured anf sculpted this film for 12 years it is based on the book. Rau by Marathi novelist NS lnamdat. but it begins with a disclaminat, which states that the film isn't professing to be historically accurate.