Qing Yu Nian, the eldest princess and the crown prince. In " Celebrating Years," Eldest Princess Li Yunrui was actually colluding with Crown Prince Li Chengqian. Although she appeared to be deliberately getting close to the Crown Prince, making others think that she was on the same side as the Crown Prince, in reality, the Crown Prince was just a shield. The Eldest Princess had secretly colluded with the Crown Prince. The two of them had joined forces to overthrow Fan Xian. This plot was revealed and hinted at in the TV series "Celebrating Years".
The Eldest Princess had a relationship with three men in the Qing Dynasty. They were Prime Minister Lin Ruofu, Crown Prince Li Chengqian, and the Qing Emperor. In the original novel, the Eldest Princess and the Qing Emperor were siblings, but in the television series, they were described as " not blood relatives." The Eldest Princess had secretly colluded with the Second Prince. The two of them worked together to overthrow Fan Xian. Thus, the Eldest Princess had an affair with the Qing Emperor and the Second Prince in the Qing Dynasty.
In the 'princess of the king novel', the identity of the princess of the king would depend on the context and the story's development. It's possible that she is the daughter of the king, in which case she might be heir to the throne or have certain responsibilities within the kingdom. Or she could be a princess from another land who is betrothed to the king, bringing with her political alliances and cultural exchanges. However, without more information about the novel, we can only speculate.
Princess Kadin ended up with Stirling. In " Purple River," Princess Kadin was the princess of the demon race. However, after the rebellion was quelled, Stirling became the new president. Therefore, he married Princess Kadin in order to draw the relationship between the two races. In addition, Princess Kadin married Yun Qianxue and gave birth to a son named Stirling. Therefore, according to the information provided, Princess Kadin and Stirling were together.
The Eldest Princess was actually on the same side as the Second Prince. Although she appeared to be deliberately getting close to the Crown Prince, making others think that she was on the same side as the Crown Prince, in reality, the Crown Prince was just a shield. The Eldest Princess had secretly colluded with the Second Prince. The two of them worked together to overthrow Fan Xian. This plot was revealed and hinted at in the TV series "Celebrating Years". Thus, the Eldest Princess and the Second Prince were in cahoots.