Ruler of Kuwait is dead at 91.

State television announced his death on Tuesday after reciting Muslim prayers and Quranic verses.

Hours later, the National Assembly Speaker Marzouq Al Ghanim tweeted that his brother Sheikh Nawaf, 83, would be sworn in on Wednesday by taking an oath in parliament.

The news of Sheikh Sabah’s death comes just two months after the nonagenarian Arab ruler was flown to Rochester, Minnesota, in a U.S. Air Force C-17 for treatment at the Mayo Clinic,days after undergoing unspecified surgery at home.

Kuwait has been a staunch U.S. ally since the American-led war that expelled occupying Iraqi troops.