HE was the billionaire philanthropist that King Charles counted as a close friend – and who made the late Queen’s horse-racing dreams come true. The Aga Khan, spiritual leader to 15 million Ismaili Muslims around the world, who has died aged 88, led a colourful life that saw him charm the Royal Family, marry a British model and become one of the world’s most extravagant playboys. He was the owner of kidnapped Derby winner Shergar who refused to pay the £2million ransom demanded by its IRA abductors in 1983.

It was Prince Karim Aga Khan who helped to fulfil the Queen’s wish of winning the Gold Cup at Ascot in 2013 with her filly, Estimate, which he gave her as an 80th birthday present. The Queen was famously pictured beaming as her horse romped home over the finishing line — the first win for a reigning monarch in the race’s 207-year history. The victory was the zenith of a friendship forged through a shared love of all things horse-racing.

King Charles was yesterday said to be “deeply saddened” by the Aga Khan’s death after he became “a personal friend of many years”. The King is believed to be in touch privately with the family. The Prince often appeared at state dinners and engagements alongside royals such as Princess Margaret and the Prince and Princess of Wales. He leaves behind a charitable legacy which promotes education, health and development in some of the world’s poorest countries.

A gallivanting jet-setter who wants his horses, cars and women to be fast. But while the Aga Khan will forever be remembered for his philanthropy, he was also known for his jaw-dropping £10.5billion wealth, and two marriages which cost him millions in divorce settlements. In 1964 Sports Illustrated magazine described him as “a gallivanting jet-setter who wants his horses, cars and women to be fast”.

His first wife was Sarah Croker Poole, a British model and former debutante who took the name Salima Aga Khan after they married. The daughter of a Lieutenant Colonel in New Delhi, in 1958 she was officially introduced to the Queen, the highlight of a “gentry” girl’s progression into society. The couple had three children, Princess Zahra, Prince Rahim and Prince Hussain, but the marriage ended in 1995 after 25 years.

Salimah, who had previously been married to a British lord, reportedly received a £50million payout. His 2011 divorce from second wife Princess Gabriele zu Leiningen — 27 years his junior — was similarly pricey, but almost cost him far more. The Princess, a former pop singer and the daughter of German entrepreneurs, owed her title to her first marriage to Prince Karl Emich of Leiningen. She converted to Islam for her 1998 wedding to the Aga Khan and adopted a new name, Inaara, before the couple had a son.

They split six years later and it was claimed she hired private detectives to prove her husband’s alleged affair with an air hostess. She moved to Britain, and in a highly publicised ten-year divorce battle in the UK courts — said at the time to be the costliest ever — experts predicted the Aga Khan could face a £500million bill. But the case finally collapsed and the divorce battle moved to France, where the Prince spent much of his later life, and Inaara won a £54million settlement.

Described by US magazine Forbes as one of the world’s richest royals, the Prince owned hundreds of racehorses, a yacht club in Sardinia and a private island in the Bahamas. In 2008 he commissioned a £200million high-speed yacht called Alamshar — named after one of his most prized horses — with three bedrooms and a stateroom. His main home was a palace north of Paris, which boasted a training centre for his thoroughbreds, and he flew all over the world in a Bombardier Global 7500 private jet.

Followers of the Aga Khan believe him to be a direct descendant of the Prophet Mohammed through his daughter, Hazrat Bibi Fatima. Born in 1936 in Geneva to Prince Aly Khan and his first wife Joan Yarde-Buller, the daughter of a British peer, the Prince was educated at a private boarding school. His parents later divorced and his father then married Hollywood starlet Rita Hayworth, giving his son a half-sister, Yasmin.

The Aga Khan was just 20 when he was bestowed his title, after his grandfather Aga Khan III broke with tradition to allow the honour to skip a generation, bypassing Karim’s father, Aly. The young Prince was studying Islamic history at Harvard — where his classmates then began calling him “K” and “Jesus”. His grandfather later said he made the decision “in view of altered conditions in the world” which was developing fast, with the rapid progress of atomic sciences.