Prince Karim Aga Khan, the spiritual leader of the global Ismaili community, passed away on Tuesday, leaving his tens of millions of followers across the world in mourning, the Diwan of the Ismaili Imamat said in a statement in the wee hours of Wednesday.

Hussaini, the Aga Khan — the title given to the imam of the Nizari Ismailis, a branch of Shia Islam — died February 4 in Lisbon at the age of 88. He led a major development aid foundation.