When the time came to commemorate their father’s death, palace insiders say, the princes carried out separate tomb-sealing rituals: two teams of masons, two teams mixing cement, two solemn ceremonies.

The joke here is that with all this parallel activity, there might as well be one sultan of Surakarta: Pakubuwono XXVI.

Image Tejowulan, one of two half brothers claiming the throne of the Solo sultanate, in meditation on the island of Java. Credit... Justin Mott for The New York Times

Or perhaps there are none.

When the older prince, Hangabehi, 60, expelled the younger one, Tejowulan, 52, a sister who was the keeper of the keys was exiled from the palace along with him and hid the keys, according to a historian who has made it his business to follow the palace intrigues.

With the keys out of reach, neither those inside the palace nor those outside could open the giant padlocked doors of the chamber where palace treasures and ritual objects are kept, said the historian, Soedarmono, a professor at the State University of Indonesia here.

As a result, neither coronation included all the rites and the relics needed to anoint a Surakartan king, he said.

“There is no king,” said Mr. Soedarmono, who has just one name, like many Indonesians. “Neither one is king. When you write about them, you can just call them mister.”