He's 67 and balding but Tamil actor Rajinikanth is a superstar action hero with a slew of hits behind him - and a huge challenge ahead.

The one-time bus conductor, who goes by one name and is worshipped as a god by his army of followers in the more than 50,000 fan clubs devoted to him, is about to enter the political arena.

He announced his move on New Year's Eve, stating that he will start his own political party to contest state assembly elections in Tamil Nadu in 2021.

Tamil Nadu has been dominated by strong personalities such as Ms J. Jayalalithaa of the All India Anna Dravida Munnetra Kazhagam (AIADMK) and Mr M. Karunanidhi of the Dravida Munnetra Kazhagam (DMK) for nearly five decades.

But the prosperous southern state has been in a state of political turmoil since the death of Ms Jayalalithaa early last year.

The ruling AIADMK has been engulfed in infighting among different factions, while the DMK's Mr Karunanidhi is 93 and in poor health.

Mr Rajinikanth - known as Thalaivaa, or leader, to his fans - now hopes to give Tamil voters an alternative to the established parties.

"I'm not in politics for name, fame or money. I have enough of it," he said, while pledging an "honest and corruption-free" government and to resign in three years if he is unable to fulfil his promise.

A day after his announcement, the superstar, who has fans in countries such as Japan, set up a website - https://rajinimandram.org - and asked people to register and become members.

He has yet to announce the name of his party.

And fans can rest easy: Mr Rajinikanth has not said he is quitting movies. He has a science fiction film shot in 3D - called 2.0 - coming out in April, and gangster film Kaala is expected to be released this year.

Born as Shivaji Rao Gaekwad on Dec 12, 1950, the actor is originally from the state of Maharashtra but his family settled in the southern state of Karnataka.

His mother Jijabai was a housewife and his father Ramoji Rao Gaekwad, a police constable. Mr Rajinikanth, the youngest of four children, completed his education in both private and public schools.

He started dabbling in acting while working as a bus conductor and decided to enrol in the Madras Film Institute in Chennai, where he learnt Tamil.

His first film was Tamil production Apoorva Raagangal in 1975. He had a minor role as the husband of one of the main characters, but managed to gain attention.

Since then, he has acted in more than 200 films in Tamil, Telugu, Kannada and Hindi.

Yet he remains most popular in Tamil Nadu and has come to be known for his trademark moves, such as flipping a cigarette with his hand and catching it in his mouth, and his famous one-liners, such as "This is Rajini's style" in 1977 film Aadu Puli Aattam, in which he played a character called Rajini.

On screen, his appearance remains youthful as he pulls off gravity-defying action stunts for his roles and acts opposite heroines who are sometimes half his age.

Yet off screen, he has not bothered to hide the fact that he has aged. He is married to Indian film producer and playback singer Latha Rajinikanth. The couple have two daughters - Aishwarya, 35, and Soundarya, 33 - both of whom are film directors.

Mr Rajinikanth's movies remain big events, with fans offering prayers at temples and hundreds camping outside cinemas for the first shows, which can be held as early as 4am.

When Tamil film Kabali, in which he pays an ageing gangster in search of revenge, came out in 2016, some businesses gave their employees the day off to avoid mass absences.

Still, political analysts say it will not be easy for the superstar in the world of politics.

"He is not a political man. He is an actor and he doesn't understand the problems of state and the aspirations of the people. He doesn't have the political experience," said Professor Ramu Manivannan, head of the department of political science and public administration at the University of Madras.

He noted that other actors-turned-politicians, such as Mr M.G. Ramachandran, popularly known as MGR, and Ms Jayalalithaa - both former chief ministers - had worked in different capacities before becoming leader of their party.

"Running a fan club is different from running a political party. That would be his biggest challenge," said Prof Manivannan.

There is also uncertainty surrounding the issues which Mr Rajinikanth will promote and on whether he will run counter to the Dravidian politics of Tamil Nadu. He has merely said that he will practise spiritual politics and not bring in caste or religion.

The Dravidian movement, specific to Tamil Nadu, is rooted in atheism and rationalism.

Speculation is also rife about whether Mr Rajinikanth will align himself with Prime Minister Narendra Modi's Bharatiya Janata Party, which has been trying to make inroads into Tamil Nadu and has announced that it will support Mr Rajinikanth.

Yet his fans hope that their idol will triumph in Indian politics just as his characters do in reel life.

Professor S.K. Karthik, an engineering professor at PGP College of Engineering and Technology in Tamil Nadu, has registered himself on Mr Rajinikanth's website and convinced 40 other people, including family members, to register too.

"We will give him a chance. The first attraction (to Rajinikanth) is because of his films. And then it is because he has reached such heights but he is simple," said Prof Karthik, 33. "He is coming into politics because he wants to do something for the people of Tamil Nadu. He will definitely do well. We have hope in him."