"I was thrilled by the fellow's fragile health,powerful eyes, and chiselled face. The dark skin...was an advantage." K Balachander on a young man he cast in Apoorva Raagangal, which released #onthisday in 1975. The young man was @rajinikanth. Here's how this came to be:

When the young man named Shivaji Rao Gaekwad, applied for a spot at the Madras Film School, one of the people who interviewed him was the legendary filmmaker Puttanna Kanagal, who served as a mentor. The institute training was like 'a visiting card', recalled the young man later.

When K Balachander came to deliver a lecture at the Institute, young Shivaji was blown away. Another lecturer who knew Balachander arranged for them to meet. Impressed, he offered him a role, on one condition: that Shivaji learn Tamil. Shivaji agreed and touched his feet.

According to a friend, he learned Tamil in less than three weeks. When Balachander next met him, he was shocked at how fluent he was in the language. Only one thing remained: to change his name. There was already a Sivaji Ganesan, and Kollywood wasn't big enough for one more.

So Balachander improvised: In the film 'Major Chandrakanth', no, not @reduvid, AVM Rajan had played a character named Rajinikanth. Balachander chose that name for his protege. The day on which this was done was Holi. For many years, Balachander would fondly recall this moment.

The casting was strange for the times. Who would cast a dark-skinned man for any role? But Balachander was no ordinary director.

The famous first shot of Rajinikanth was shot on March 27, 1975, and it was as dramatic as the young man's career would be. It showed him throwing open a gate and entering. Contrary to popular belief, it wasn't shot at one go - it took five or six takes.

His first line in the movie was directed at, of all people, the other man with whom he would dominate the box office for decades: @ikamalhaasan! (Clip: )

When the shoot was done, Rajinikanth went home to Bangalore, leaving a satisfied Balachander. In an interview, the latter noted that he was introducing a new boy, and he would do very well.

The movie released on August 18, 1975, and became a box-office hit, establishing a career. Rajinikanth would see the movie in Bangalore's Kapali theatre, and famously started crying in joy after seeing the movie. Safe to say that he's never looked back since then!

For more on the Superstar, read @namanrs's Rajinikanth: The Definitive Biography