Nasser David Khalili is a British-Iranian property developer, art collector and philanthropist based in London. He holds both United Kingdom and United States citizenship.His Islamic art collection extends to 20,000 items and is the largest of its kind held privately in the world.

In the Sunday Times Rich List 2007 ranking of the wealthiest people in the UK he was placed 5th with an estimated fortune of £5,800 million. This included an estimated value of £4,500 million for his art collection.

The story behind how Nasser David Khalili built his fortune has long been shrouded in secrets. As a property developer, he shunned publicity and didn’t slap his name on buildings or the company that is his main investment vehicle. He has also operated under the radar when buying art.

“During the collecting, I don’t say anything,” Khalili says. “When it’s done, then I speak.”

His elusiveness has fueled much speculation, often revolving around how he financed his collecting. Khalili, who left Iran in 1967 with $750, says he’s since spent $650 million on art. London’s Sunday Times, which estimated his fortune at 5.8 billion pounds in 2007, gave up guessing his worth the following year and removed him from its annual rich list.