The Aga Khan IV, the spiritual leader of Ismaili Muslims and one of the world’s most prominent philanthropists, died in Portugal at the age of 88, according to his community and the Aga Khan Development Network. His son, Prince Rahim Al-Hussaini, was named Aga Khan V in accordance with his father’s will, the Ismaili community said.

Karim Al-Hussaini became the Aga Khan at 20, while still an undergraduate at Harvard, after his grandfather passed over his father and named him successor to the hereditary Imamate. The AP report says the choice was framed by the elder Aga Khan as a way to give the community a leader “brought up in the midst of the new age,” and that the young Karim left school briefly to be with his ailing grandfather before returning to Harvard with a sense of obligation that shaped the rest of his life.

Over the decades, the Aga Khan became both a religious figure and a global business and philanthropic power. His Aga Khan Development Network focused on health care, housing, education and rural economic development, and the AP report said it operated in more than 30 countries with an annual nonprofit budget of about $1 billion. The network’s hospitals, schools and development projects gave the imam a public role far beyond theology, especially in places where basic services were limited.

The AP described him as a bridge between Muslim societies and the West, a leader who moved easily between spiritual authority and worldly influence. He was given the title “His Highness” by Queen Elizabeth II in 1957, and later became a familiar presence at public ceremonies, university events and diplomatic gatherings around the world. He was also well known in the equestrian world and among charities tied to his development work.

His death prompted tributes from international figures including U.N. Secretary-General António Guterres and Canadian Prime Minister Justin Trudeau, who both praised his compassion and his role in promoting tolerance. The Ismaili community said burial would take place in the coming days, followed by an homage ceremony. For followers spread across South Asia, Africa, the Middle East, Europe and North America, the succession to Aga Khan V marks the start of a new chapter for a community whose leadership is both spiritual and institutional.

The succession is likely to be watched closely because the Aga Khan’s authority combines religious leadership, philanthropy and institutional stewardship. Rahim Al-Hussaini now inherits that mix of responsibilities, along with a global network that has long been central to the community’s identity.