President Xi Jinping has sent a congratulatory letter to the Association of National History of the People's Republic of China on its 30th founding anniversary.Xi, also general secretary of the Communist Party of China Central Committee and chairman of the Central Military Commission, called for remaining confident in our history, exhibiting greater historical initiative, and better building a powerful source of inspiration to strive in unity.President Xi Jinping has sent a congratulatory letter to the Association of National History of the People's Republic of China on its 30th founding anniversary.Xi, also general secretary of the Communist Party of China Central Committee and chairman of the Central Military Commission, called for remaining confident in our history, exhibiting greater historical initiative, and better building a powerful source of inspiration to strive in unity.