Please recommend an ancient fictional novel. The male protagonist is a prince (or emperor), and the female protagonist is a princess from a neighboring country. The plot involves the female protagonist assassinating the male protagonist and an accidental exchange of souls.

The story of Nangong Ling and the princess of the neighboring country was one of the common plots in Mary Sue's novels. It often described the love story between a handsome, intelligent, and rich prince of the neighboring country and a beautiful, intelligent, and independent girl. Such novels usually involved political marriages, power struggles, family revenge, and other elements. At the same time, there were often various misunderstandings, contradictions, and misunderstandings that eventually led to the breakup or divorce of the two.

I recommend "When It's Fainty" to you. The female protagonist of this book is called Zhao Mingxi. She is a princess from the previous dynasty, and her mother is a princess from a neighboring country. The male lead, King Yu, was a prince, while the female lead's cousin was the prince of a neighboring country. In the end, the second male lead, the prince of the neighboring country, became the emperor, but his eyes were not good. I hope you like this fairy's recommendation. Muah ~😗

Which novel series or storyline does this question appear in? Can you provide more background information? This way, I can better provide you with an answer.

I recommend "Reporting to Your Highness, Your Highness Wants to Get Married!" This was an ancient romance novel about a transmigrator who disguised herself as a man and entered the palace. The male protagonist was an arrogant and cold prince, while the female protagonist was a kind and passionate princess. Their relationship was full of sparks and quarrels, but in the end, they were still able to come together with mutual help and support. I hope you like this fairy's recommendation. Muah ~😗

The male protagonist was Nangong Yan, and the female protagonist was a princess who married into a neighboring country. This was a fantasy novel about time travel. After the two-faced killer Jiang Qingyue transmigrated into a useless princess, she began a fantasy journey. The male lead was a man full of hostility, but in front of the female lead, he had a different side. Their story was full of thrills, excitement, and love. I hope you like this fairy's recommendation. Muah ~😗

I recommend "After Rebirth, I Became the Empress Dowager". The male protagonist of this book is the emperor of a country, and the female protagonist is an orphan of the previous royal family. After her rebirth, she replaced the princess of another country in marriage. This was an ancient romance novel. The plot was complicated, and the character settings and emotional descriptions were very detailed. The female protagonist was very smart, decisive, and thoughtful. She was not just a passive female character. I hope you like this fairy's recommendation. Muah ~😗

😋I recommend "Soul Exchange: The Chef Becomes the Emperor." This ancient romance novel described the female protagonist who failed to escape from marriage and transmigrated to the emperor, while the male protagonist was the real emperor. The female protagonist faced the schemes of the Empress Dowager and her brothers, unable to shake off her fatigue and pressure. One day, when the real Emperor returned, how would the female protagonist respond? The plot is fictional and cannot be imitated. I hope you like this fairy's recommendation. Muah ~😗

😋I recommend the book 'The Truth Is Revealed, My Soul and His Highness's Exchange' to you! The souls of the male and female protagonists were exchanged. The male protagonist was once the emperor, and the female protagonist was his concubine. The male protagonist had once been instigated by someone to cause her family to die tragically. After the two souls exchanged, the female protagonist saw the male protagonist's desolation and cruelty and wanted to pay back the things he had done to her one by one. I hope you like this fairy's recommendation. Muah ~😗

The name of this time-travel novel was " Time Travel and Anti-Time Travel ", and the author was Yanyu Jiangnan. The story was about a modern girl who traveled to an ancient dynasty and became the concubine of the seventh prince. However, she soon found out that the seventh prince was actually the prince of a neighboring country, and her prime minister husband was also the prime minister of a neighboring country. During her time with the prince of the neighboring country, she gradually revealed the secret between herself and the people around her and experienced a complicated emotional entanglement. The plot of this novel was full of ups and downs. It was a very exciting time-travel novel.

Unfortunately, according to the given novel information, I couldn't find a novel that matched the description. He might need to provide more details or re-describe the plot of the novel.