The Aga Khan Prince Karim Al-Hussaini, spiritual leader and friend ...

Aga Khan IV, the spiritual leader, racehorse owner and friend of Queen Elizabeth II, has died aged 88.

Despite spending most of his life out of the limelight, the Aga Khan was the spiritual leader of about 12 million people from the Ismaili sect of Islam.

Some of his followers believed he was the direct descendant of the Prophet Mohammed.

A notice on the website of the Aga Khan Development Network - the development organisation he founded - announced his death, saying that he "passed away peacefully in Lisbon on 4 February 2025... surrounded by his family".

It said: "His Highness Prince Karim Al-Hussaini, Aga Khan IV, 49th hereditary Imam of the Shia Ismaili Muslims and direct descendant of the Prophet Muhammad (peace be upon him), passed away peacefully in Lisbon on 4 February 2025, aged 88, surrounded by his family.

"Prince Karim Aga Khan was the founder and chairman of the Aga Khan Development Network.

"The announcement of his designated successor will follow.

"Leaders and staff of the Aga Khan Development Network offer our condolences to the family of His Highness and to the Ismaili community worldwide.

"As we honour the legacy of our founder, Prince Karim Aga Khan, we 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."

The Aga Khan, who inherited his title of the 49th Imam of the Shia Imami Ismailis in 1957 at the age of 20, was believed to have been worth over £11bn at the time of his death.

He was born in Switzerland and spent much of his later life in France, although he had British citizenship.

He was an old friend of the late Queen Elizabeth II, who had bestowed on him the title of His Highness when he became the leader of the Ismaili Muslims.

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Much like the late royal, the Aga Khan was a huge fan of horseracing and owned various horses.

These included the famous Shergar, who was stolen by gunmen in Ireland in 1983 and never seen again.

He is survived by his children Princess Zahra, Prince Rahim, Prince Hussain and Prince Aly Muhammad, and four grandchildren.