Addressing the gathering of Congress leaders and party workers at the party headquarters here, Rahul said, "Congress took India to 21st century, but the prime minister today is taking us back to the medieval times."
"And if there is anyone who can stop what the BJP is doing, it is the 'pyara karyakarta & neta' (leader and workers) of Congress. We are going to make Congress, grand old and young party. We will fight the politics of anger," Rahul asserted.
The 47-year-old was officially made the party chief in a ceremony held at the party's 24 Akbar Road headquarters here.
He was given the certificate of Congress president by Mullappally Ramachandran, the chairman of the party's central election authority, who oversaw the organisational polls.
The ceremony was attended by party stalwarts, his mother and outgoing Congress President Sonia Gandhi, former prime minister Manmohan Singh, former union home minister Sushil Kumar Shinde, former Maharashtra chief minister Ashok Chavan and other party leaders.