Liu Ju had three sons.
The Qing Emperor had a total of five sons. From oldest to youngest, they were the Great Prince, the Second Prince, the Crown Prince, Fan Xian, and the Third Prince. Thus, Fan Xian was the Qing Emperor's fourth son.
The Qing Emperor had a total of five sons. The Crown Prince was the Qing Emperor's second son.
The Qing Emperor had a total of five sons. The Crown Prince was the Qing Emperor's second son.