JMurone

Emperor Kiritsubo had a younger brother (zen-bo前坊: meaning previous crown prince) who was the crown prince. Emperor Kiritsubo and Zenbo were born of the same mother. When Zenbo was crown prince, the Emperor Kiritsubo was just a prince. However, his brother died and Emperor Kiritsubo ascended to the throne. The author, of course, does not mention the cause of the Crown Prince’s death.　

What we can infer from this situation is the following.

The mother of the Crown Prince is considered to be the daughter or granddaughter of a minister or a member of the imperial family. The fact that the younger brother became Crown Prince before his elder brother, even though they had the same mother, is thought to be because he married the daughter of a more powerful noble than his elder brother’s wife. crown princess was called Rokujo-no-Miyasudokoro(六条御息所) and was the daughter of a minister.

This minister had already died, but a daughter of a fatherless upper aristocrat would never become the first lady of the Crown Prince. It is therefore likely that her father died after her marriage and after his son-in-law had assumed the position of Crown Prince. Miyasudokoro inherited her father’s vast estate. Her father was a great lord.

蓮華寺（Renge-ji）京都フリー写真素材　

In the Heian period, before The Tale of Genji was written, all the princes who held the position of crown prince but did not become emperor either lost their positions in political upheavals or died unexpectedly.