Emperor Duzong of Song

Emperor Duzong 宋度宗 was the 15th emperor of the of China, and the sixth emperor of the Southern Song. His personal name was Zhao Mengqi . He was the nephew of Emperor Lizong and reigned from 1264 to 1274.
Duzong's reign was plagued with rebellions, warfare and upheaval. The Mongols had spent decades harassing the borders of the Southern Song and were on the verge of conquering the whole of China. Duzong totally ignored his duties and instead delegated all state and military affairs to the hands of his incompetent minister named Jia Sidao; the emperor instead indulged in drinking and women and lived in opulence. At first, he told the officials to be straightforward and tell him the problems in the countries, but this was all an act. Soon, he completely neglected his duties. Furthermore, he had a very high sexual appetite. Under the Song's law, any female who had a sexual relation with the emperor needs to come pay respect to the emperor in the morning. At one point, there were as many as 30 females one morning paying respect.
The was fought in Xiangyang in 1274 when the Mongols succeeded in capturing and destroying the last Song stronghold. The defeat and the loss of Xiangyang sealed the fate of the Song dynasty and the news of its capture was deliberately hidden from Duzong by Jia.

Duzong died shortly thereafter and was succeeded by his four year old son. Although technically not the last emperor of the Song dynasty, Duzong was considered the last emperor of the Song dynasty that could have made a difference in changing the outcome or perhaps even averting the fall of the dynasty.