Prime Minister Narendra Modi on Thursday greeted the nation on the Constitution Day being marked here for the first time.
"Greetings to people of India on the historic occasion of 1st Constitution Day. May this day inspire you to know more about our Constitution," Modi said in a tweet.
The Constitution of India was adopted on November 26, 1949 before it came into force on January 26, 1950.
He said this day was in honour of all the great people who worked tirelessly towards making the Constitution.
"No mention of our Constitution is complete without remembering the stellar contribution of Dr. Babasaheb Ambedkar. I salute him," he added.
In a tribute to B.R. Ambedkar, widely regarded as the architect of the Indian constitution, the parliament will hold a special sitting on Thursday and Friday.
The two-day event will be a part of year-long nationwide celebrations to mark the 125th birth anniversary of Ambedkar.
