A striking share of Hindi cinema's founding families came from Punjab and the frontier, and most of them left in or before 1947.
Prithviraj Kapoor came from Peshawar, founded Prithvi Theatres, and his descendants have been in Indian cinema for four generations. Dilip Kumar, born Mohammed Yusuf Khan, was from Peshawar. Dev Anand was born at Shakargarh in Gurdaspur district. Sunil Dutt was from Khurd in Jhelum district. Rajendra Kumar was from Sialkot. B.R. and Yash Chopra were from Lahore.
Behind the camera the pattern is the same: directors, writers, composers and lyricists from Lahore, Amritsar, Ludhiana and the frontier.
The reason is straightforward. Lahore had a film industry, and when it was cut off in 1947 the Hindu and Sikh half of it moved to Bombay with the skills and the contacts.
Hindi cinema's Punjabi accent, its wedding songs, its family structures and its idea of what a hero looks like all come from that migration, and audiences across India absorbed a Punjabi cultural template through it without particularly noticing.
Lahore had four working studios before 1947 and made films in Punjabi, Urdu and Hindi. What moved to Bombay was not only people but a whole production culture, and what stayed behind became the Pakistani industry.
The Bombay film industry's Punjabi component came in two waves: the pre-war migration to the studios, and the 1947 arrival of people who had lost everything in Lahore.
The result is that the language, the music and the family sentiment of a Hindi film are substantially Punjabi, and have been since the 1950s.
Biographies of the individuals named.