Chinese leader Xi Jinping has formally etched his name alongside the greatest figures in the annals of Communist Party history, paving the way for him to strengthen and extend his rule over the world’s most populous country.

China’s most senior officials approved a resolution on the party’s accomplishments since its founding 100 years ago that portrays Mr. Xi as a core leader who has “promoted historic achievements and historic changes.” The decision puts him on equal footing with revolutionary patriarch Mao Zedong and market reformer Deng Xiaoping, the only other leaders who enjoyed enough power to push through resolutions on the party’s history.

The elevation of Mr. Xi’s official status was a centerpiece of the annual fall gathering, or plenum, of nearly 350 full and alternate members of the Communist Party’s Central Committee in Beijing, according to the communiqué. The resolution ensures longevity for Mr. Xi’s agenda and armors him against criticism because that would require challenging the party’s narrative of history.

“Not everyone in the party is convinced that this centralization authority and the valorization of a supreme leader is the best way to build the party and strengthen China,” said Timothy Cheek, a professor at the Institute of Asian Research at the University of British Columbia. “The historical resolution will decidedly answer those concerns, claim the moral high ground and, importantly, define political disagreement or dissent as disloyalty and treachery.