[Read live updates to China’s National Day parade and Hong Kong protests.]

The pageantry of the 70th anniversary reveals how thoroughly the party has rewritten China’s past to reflect Mr. Xi’s turn to communist traditionalism — what he calls reviving the party’s “red genes.” He offers an unabashedly triumphant vision of China’s past, and its future. It is a patriotic message that resonates with many Chinese, even in Xinyang, a region of rural counties and towns that suffered greatly under Mao.

“This red land was hard won and paid for with the fresh blood of tens of millions of revolutionary forebears,” Mr. Xi said when he honored revolutionary “martyrs” in Xinyang in mid-September, according to an official account. “We must always recall where red power came from and cherish the memories of our revolutionary martyrs.”

In his seven years in power, Mr. Xi has acted on the belief that to control China he must control its history. His administration has molded textbooks, television shows, movies and museums to match his narrative of national unity and rejuvenation under iron party rule.

Under him, the Communist Party has promoted revolutionary nostalgia and played down the strife of the Mao era. The anniversary celebrations, which culminate on Tuesday with a military parade in Beijing, have reinforced this rosy depiction of the past 70 years as a near-uninterrupted march of economic and technological progress, enshrining them through oversize floral displays in Beijing. On Monday, Mr. Xi paid his respects to Mao’s preserved body in a mausoleum in Tiananmen Square.