Zhao Dezhao

Zhao Dezhao (趙德昭) (951-979) was an imperial prince of the Chinese Song Dynasty. Officially the Prince Yi of Yan (燕懿王), he was the second son of Emperor Taizu and the crown prince since his elder brother died young. However, he did not succeed the throne after his father, as his uncle Emperor Taizong assumed power.
In 979, 3 years after his father's death, Zhao Dezhao was leading an army in Emperor Taizong's first campaign against the Khitans, when rumors spread in the army that Emperor Taizong had disappeared, and that Zhao Dezhao should be the new emperor. The rumors died when Emperor Taizong was found, however, Emperor Taizong was very unhappy and refused to award the troops. Zhao Dezhao went to inquire the emperor, who barked "You do that when you become the new emperor!" Zhao Dezhao immediately went to his palace and asked his guards for a sabre. The guards told him that blades were not allowed in the palace, so Zhao Dezhao fetched a knife for cutting fruits and sliced his throat. Upon hearing about the suicide, Emperor Taizong was very saddened and hugged the corpse crying.
However, as official history may not be trusted in events like this, some historians suspect that Zhao Dezhao was either murdered or forced to commit suicide by his uncle, who possibly was also involved in the deaths of Zhao Dezhao's father and younger brother. Zhao Defang, the last surviving son of Emperor Taizu, died 2 years after Zhao Dezhao. He was also in his 20s.