Aga Khan IV, the 49th imam of the Ismaili Muslims and philanthropist, died on Tuesday. He was 88.

He “passed away peacefully” in Lisbon, Portugal, surrounded by his family, the Ismaili community said in a statement.

His successor will be announced soon, the statement added.

Aga Khan is survived by three sons and a daughter.

The Ismaili community, with an estimated 12 million to 15 million members, resides mainly in central and southern Asia, West Asia and eastern Africa. The Ismailis are a Shia Muslim sect.

He had led the community since 1957, when his grandfather Sir Sultan Mahomed Shah, or Aga Khan III, had named him as successor, passing over his father.

Aga Khan, or Karim Al-Husseini, was the founder and head of global charities Aga Khan Development Network and the Aga Khan Foundation that fund development programmes mainly in Asia and Africa.

Aga Khan held citizenship of the United Kingdom, France, Switzerland and Portugal and was based in Lisbon. His personal wealth was estimated to be in billions, according to some reports.

Prime Minister Narendra Modi expressed his condolences, saying that Aga Khan was a “visionary, who dedicated his life to service and spirituality”.

Modi added: “His contributions in areas like health, education, rural development and women empowerment will continue to inspire several people”.

Aga Khan was awarded the Padma Vibhushan, India’s second-highest civilian honour, for social work in 2015.

United Nations chief Secretary-General António Guterres praised Aga Khan as a “symbol of peace, tolerance and compassion”.

Aga Khan’s charities operate several hospitals, educational institutions and cultural programmes mainly in developing countries.

The Aga Khan Development Network said that it will “continue to work with our partners to improve the quality of life for individuals and communities across the world, as he wished, irrespective of their religious affiliations or origins”.