Bali: An Indonesian sultan who defied centuries of tradition by declaring that his daughter will succeed him is facing an uprising by his relations.

Hamengku Buwono X, the Sultan of Jogjakarta, Java, had announced in 2015 that Princess Mangkubumi, his eldest daughter, was to succeed him, much to the consternation of his relations.

Now it has emerged the 72-year-old sultan's brothers and sisters are outraged by the decision. They are refusing to attend royal events and have threatened to expel his wife and daughters after his death.

The modernising sultan, who is also governor of the modern Special Region of Jogjakarta, ascended to the throne in 1989, and discontinued the polygamist tradition of Javanese royalty having multiple wives and concubines. In 2006, when Mount Merapi, the most active volcano in Indonesia, began spewing a deadly cloud of hot ash, gases and rock fragments, he told locals to heed the warnings of scientists rather than his own palace-appointed fortune tellers about when to evacuate.

However, his 2015 decision to pass the sultanate to the eldest of his five daughters instead of a male descendant has caused the biggest controversy yet.