The biological son of late Taiwanese president Chiang Ching-kuo has finally taken his father's last name to become a member of the family which ruled the island for four decades after 1949. The sole surviving son of the late leader had previously used the family name of his mother, Chang Ya-juo. He is now called John Chiang Hsiao-yen, a title kept out of reach for more than 30 years. 'I applied for the name change at the census office on March 2,' he said, adding that the revision completed his long journey to be recognised as part of the Chiang family. He and his twin brother, Winston, were born out of wedlock to Chiang and his mistress in Guilin , Guangxi, in 1941. Their mother died during their childhood on the mainland. Their father later arranged to bring them to Taiwan. To cover up the affair, their uncle and aunt on their mother's side became their parents. He kept his mother's last name to show respect to her and to avoid embarrassing the official wife of the late president, Faina Chiang Fang-liang. Following her death in December last year, he decided to take up his family name.