Chiang Ching-kuo never acknowledged his twin sons, and one of them took the Chiang name 63 years later

Chang Ya-juo was a mistress of Chiang Ching-kuo, son of Chiang Kai-shek. On 1 March 1942 she gave birth to twin boys in Guilin. On 14 August 1942, after a dinner with friends, she fell ill with vomiting and diarrhoea, went to hospital the next morning and died. Her mother, brother and sister-in-law raised the twins under her surname, Chang. The uncle and aunt were listed as their parents on official papers until 2002. The boys learned who their father was in high school. Chiang Ching-kuo became president in 1978 and died in 1988 without acknowledging them. Winston Chang became president of Soochow University, had a stroke in Beijing in 1994 and died in February 1996. John Chang served as foreign minister in 1996 and 1997. In 2002 he had his aunt's hair tested to show she was not his mother, and by the end of that year his ID card named Chiang Ching-kuo and Chang Ya-juo as his parents. After Chiang's widow, Faina, died in December 2004, he changed his surname to Chiang in 2005. His twin's family opposed the change. No DNA comparison with the Chiang family has been made, and the family has not formally recognised him. In 2020 a researcher at the Hoover Institution cited a 1985 CIA paper listing Chiang Ching-kuo as his father. His son, Chiang Wan-an, born Chang Wan-an, was elected mayor of Taipei on 26 November 2022 and holds the office in 2026.