There have been many superstars in Bollywood but none can match the enduring magic or the towering personality of Amitabh Bachchan.

Amitabh, who was discharged from hospital Saturday after almost three weeks following a stomach surgery, was the object of concern of millions of his fans across India and the world as they prayed for his recovery.

The loyal following the 63-year-old actor still commands in the face of younger stars like Shah Rukh Khan, Salman Khan or Akshay Kumar is amazing.

The news-hungry media kept constant tabs on the latest about the superstar for the information of his fans. All television channels flashed his discharge Saturday from the hospital as "breaking news".

The longevity of Amitabh's superstardom has surprised all and sundry.

In the past too superstars like Dilip Kumar, Dev Anand and Rajesh Khanna enjoyed immeasurable popularity during their prime. Unlike Amitabh, their fame dimmed once they were past their prime, but this mega star shows no signs of losing his grip at the top.

So what makes Amitabh go on and on and on and stay at the peak?

TV personality Shekhar Suman says: "He was born as a special man with a special horoscope and entertained people in various ways. He redefined the image of a hero."

More than two decades ago, when Amitabh was hurt during the shooting of the film "Coolie" in 1982, a similar kind of panic gripped the entire nation.

A lean phase followed his recovery in 1982 but Amitabh re-invented himself as a showman with the TV game show "Kaun Banega Crorepati".

He debuted in Bollywood with Khwaja Ahmad Abbas' "Saat Hindustani" (1969) and struggled for four years for a hit. In 1973, with the success of Prakash Mehra's "Zanjeer", his career took off and there was no looking back for the tall and lanky young man.

In the years that followed, he emerged as the "angry young man", a messiah of the poor who stood up against burning social issues of the time - injustice, poverty and corruption.

Commenting on Amitabh's larger than life image, Shekhar Suman says: "The people who were jobless, poor and angry with the system identified with him and started idolizing him. He looks larger than life not only in reel life but in real life too."

Amitabh isn't what you would call conventionally handsome. His height and his voice, both of which set him apart, were at one time considered handicaps. But later they became his assets and made him arguably the biggest star Indian cinema has ever produced.

"I think popular would be an understatement", says filmmaker Meghna Gulzar, lyricist-script writer Gulzar's daughter.

"He is not only a national but an international icon because of his body of work."

Asked whether popular concerns over his health were justified, Meghna told IANS: "If you look at him as an icon, it is justified. It shows people are concerned. These are all signs of adulation and care.

"There is no right and no wrong because people are not intruding into the lives of the stars. They are just showing their concern by being there."

If in his prime Amitabh was working several shifts a day, even today he works 18 hours a day.

Amitabh is one of Bollywood's busiest and most visible actors. He is everywhere - his face stares out of magazines, newspapers, TV commercials and, of course, films. In his free time, he works as brand ambassador for numerous products besides shooting for "Kaun Banega Crorepati - 2".

So should Amitabh Bachchan continue this kind of hectic life at this age?

"No," says well-known film critic Taran Adarsh. "He needs to slow down a little. You need to look after your health because it is very important."

Amitabh's sudden illness not only worried his numerous fans but also sent a wave of panic through the entertainment industry, as he is involved in several projects worth Rs.2.7 billion (about $60 million).

But Adarsh says: "He has completed all his films except Ravi Chopra's 'Babul'."

The first film to hit the screen after Amitabh was hospitalized was Apoorva Lakhia's "Ek Ajnabee" where he plays the protagonist. Unfortunately the film failed to repeat the success of Manmohan Desai's "Coolie" - the first film to hit the screen in 1983 after his earlier accident.

"Family - Ties Of Blood" will follow "Ek Ajnabee".

Amitabh is also working with almost all the younger generation directors. He is in Karan Johar's "Kabhi Alvida Na Kehna" to be released early next year.

His other films include Ravi Chopra's "Babul" where he is paired with Hema Malini again after "Baghban". Rani Mukerji and Salman Khan also star in it.

He has Vidhu Vinod Chopra's "Eklavya" which also stars Sanjay Dutt, Saif Ali Khan and Vidya Balan, besides Ram Gopal Varma's "Darna Zaroori Hai" and "Sholay".

Rohan Sippy, whose film "Bluffmaster" starring Abhishek Bachchan, Priyanka Chopra and Riteish Deshmukh hit the screen during the weekend, is a great admirer of Amitabh.

"He is more than an institution, he has become an icon for all of us. We identify strongly with him," says Rohan.