The song "Pyar Kiya To Darna Kiya" has an unusual history to it: it cost Rs. 10 million at a time when a film would be made for less than a million; it was written and re-written 105 times by the lyricist, Shakeel Badayuni, before the music director, Naushad, could approve of it; it was shot in the renowned Sheesh Mahal (Palace of Mirrors); and in those days of sound recording, editing and mixing, as there was no way to provide the reverberation of sound, Naushad had playback singer Lata Mangeshkar sing the song in a studio bathroom.
It took 16 years for the movie to be complete.
The first full feature-length movie to be revived/colorized for a theatrical re-release in the history of world cinema. It has been done for some Hollywood movies but only for re-release on home video.
This was (counting Sanjay Leela Bhansali's Devdas) the most expensive film ever made in Indian history. Tailors were brought from Delhi to stitch the costumes, specialists from Surat-Khambayat were employed for the embroidery, Hyderabad goldsmiths made the jewellery, Kohalpur craftsmen designed the crowns, Rajasthan ironsmiths crafted the weapons, and the elaborate footwear was ordered from Agra. For the battle sequence, 2000 camels, 4000 horses and 8000 troops were used, many of them soldiers on loan from the Indian Army. Altogether the film cost Rs. 1.5 crores (38.29 crores in present terms).
The heavy chains Madhubala wore in the film were authentic, not the lightweight models worn in those days. It was her greatest ordeal in the film and she was bedridden for days, nursing the bruises caused by wearing those chains.