Short answers, pulled from the story.
The four historical capitals of China located in Henan are Luoyang, Anyang, Kaifeng, and Zhengzhou. Each served as a seat of power across different dynasties spanning thousands of years of Chinese history.
The Banqiao Dam in Biyang County collapsed in August 1975 when Typhoon Nina brought rainfall that exceeded the capacity of sixty-two dams across central and southern Henan. At least 26,000 people were killed, with unofficial estimates including epidemic and famine deaths ranging as high as 230,000, making it the deadliest dam-related disaster in human history.
Henan had a population of over 99 million as of the 2020 census, making it China's third-most populous province and the most populous among inland provinces. Under the hukou registration system, which counts migrant workers as provincial residents, the figure exceeds 103 million.
Kaifeng served as the capital of the Song dynasty after China was reunified in 982. Under Song rule, Kaifeng surpassed Luoyang and Chang'an to become the largest city in China and in the world at that time.
The Nationalist government led by Chiang Kai-shek bombed the Huayuankou dam in Zhengzhou in 1938 to slow the advance of the Imperial Japanese Army after it captured Kaifeng during the Second Sino-Japanese War. The resulting floods spread across Henan, Anhui, and Jiangsu, causing hundreds of thousands of deaths.
As of 2025, three cities in Henan ranked in the top 140 cities in the world by scientific research output according to the Nature Index: Zhengzhou at 58th, Kaifeng at 136th, and Xinxiang at 138th. This places Henan among only three Chinese provinces with at least three cities in that global ranking.