His Royal Highness hosted an event celebrating the Inspiring Digital Enterprise Award (iDEA) scheme, which aims to support young people developing digital businesses, and the musician made an appearance.
"Will.i.am is a partner of mine in this (iDEA) because he's got some really good projects going on, in Los Angeles. I met him initially through the Queen Elizabeth Prize for Engineering," the Duke told Tania Bryer on CNBC Meets. "And actually funnily enough also through Sarah who knows him as well."
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"iDEA…is about giving young people the digital skills they're going to need in the 21st century," he added.
But this is not the first time The Black Eyed Peas front man has openly backed the royal family. In 2012 he met the Prince of Wales when he donated £500,000 ($828,902) of his own money to the Prince's Trust. Will.i.am gave his salary earned from presenting the BBC One series of "The Voice" to the charity, which helps disadvantaged young people.
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The singer also met and spoke to the Queen when he performed at the Diamond Jubilee concert in 2012, where he reportedly complimented her wardrobe and sense of style.