Malaysia’s king abdicated on Sunday in a historic first for the country that ended weeks of speculation about his future after he took medical leave and reportedly married a Russian former beauty queen.

Sultan Muhammad V’s decision marks the first time a Malaysian king has stepped aside before the completion of his five-year term. He had been on the throne for two years.

The 49-year-old king’s resignation took effect immediately, the National Palace said in a statement. No reason was given and palace officials did not respond to requests for comment.

Sultan Muhammad, who had resumed duties a week ago, is known for his fondness for four-wheel driving and other extreme sports.

“His majesty tells the people of Malaysia to continue to be united to maintain unity, tolerance, and work together,” said a statement from the comptroller of the royal household, Wan Ahmad Dahlan Abdul Aziz.

Malaysia’s Islamic rulers will now meet to decide on the next king. Malaysia is a constitutional monarchy, with a unique arrangement where the throne changes hands every five years between rulers of the nine Malaysian states headed by centuries-old royalty.

There had been a question mark on Sultan Muhammad’s reign since he went on leave for treatment in November. Reports in British and Russian media had then surfaced claiming that he had married a former Miss Moscow in the Russian capital in a lavish ceremony.

Royal officials in Malaysia have so far not commented on the rumoured marriage, or given any details about the state of Sultan Muhammad’s health.

While their role is ceremonial, Malaysia’s royalty commands great respect, especially from Muslim Malays, and criticising them is strictly forbidden.

The New Straits Times reported there had been tensions between the palace and the government of Prime Minister Mahathir Mohamad, who led the Opposition to an election win in May.

Mahathir, known for challenging royalty during his past 22-year tenure as Prime Minister, said in a blog post last week that everyone “from the Rulers to the Prime Minister and Ministers, to the civil servants and ordinary citizens” are subject to the law. He did not elaborate.

In June, the government and palace faced a near two-week impasse over a plan to appoint a non-Malay as attorney-general. The king eventually approved the appointment, though the incident had stoked racial tensions.

Sultan Muhammad studied at St Cross College at Oxford and the Oxford Centre for Islamic Studies, according to the official media. He is known for a relaxed public persona, taking part in walkathons to promote health, and has been photographed wearing a baseball cap backwards.

The palace statement said Sultan Muhammad was “ready to return home to the state of Kelantan to be together with the state government and... the Kelantanese people”.