Amitabh and Jaya, who won the hearts of millions across the world, tied the knot on 3 June, 1973, and since then have been acknowledged as one of the most successful Bollywood couples.
The two met each other on the sets of "Guddi" in which Jaya played the lead role while Amitabh, who was a then a newcomer, played a cameo role. They eventually fell in love and got married after their film "Zanjeer" was declared a blockbuster.
Following "Zanjeer", the couple was also seen in films like "Abhimaan", "Sholay", "Mili", "Chupke Chupke", Marathi film "Akka" and Bhojpuri film "Ganga Devi" among others. They have two children - Shweta Nanda and Abhishek Bachchan, who is married to Aishwarya Rai.
Amitabh, who stays connected to his fans through his blog and social networking sites like Facebook and Twitter, thanked all his well-wishers.
Recollecting the day of his marriage Amitabh wrote in his blog, "40 years !! 40 years of marriage on the 3rd of June 2013 .. ! Jaya and I in marriage for 40 years ..! A lifetime almost ! Seems like just the other evening I had driven with my parents to a friends place on Malabar Hill, in the Southern region of the city, and to a very quick, no fuss, no 'taam jhaam', family and a few friends, and a few close media, wedding."
"A wedding that had the fulfilment of a promise, that if 'Zanjeer' succeeded we would get married ! Here we are now, two children and three grand children, son in law, daughter in law, relatives and 'samdhi's' in our family fold. God has been very kind !" he added.
Although their anniversay called for a grand celebration, Amitabh Bachchan said his family was away for some prior commitments which were more important.
"The family is away .. in New York and in London on matters that deserve presence and attention greater than a celebration, so I stay with the memories alone .. not in the real sense, for communication is so instant rapid and finite that, distances have been reduced to a mere mention of a destination," said Amitabh in his blog.