McLaren officially opened its new factory in Sheffield yesterday, cutting the ribbon on the £50 million (~$64m) facility that will help it expand production beyond its existing facility in Woking. And on hand for the event were the princes and heirs apparent to the thrones of not one, but two countries.

Instead of sourcing the components from outside suppliers, the new McLaren Composites Technology Centre will manufacture the carbon-fiber tubs and other components for the company’s expanding line of supercars. The facility is built on the site of a former coal mile, with a 7,000-square meter (75,000-square-foot) building on a four-acre property.

The MCTC will employ some 200 people, 50 of which were already on hand for the opening. But the event also brought in some very special guests.

Their Royal Highnesses Prince William and Princess Kate, the Duke and Duchess of Cambridge, came up to Yorkshire for the grand opening of the factory, where they were joined by His Royal Highness Prince Salman bin Hamad Al Khalifa, the Crown Prince of Bahrain.

Why Bahrain, you ask? Because the Mumtalakat Holding Company – the kingdom’s investment fund – is the largest stakeholder in the McLaren Group, holding 56 percent of its shares. The Crown Prince’s son (and grandson of the king), Mohamed bin Isa Al Khalifa, serves as the company’s executive chairman, having taken over after Ron Dennis was ousted.

Only months later, in February 2017, McLaren first announced its plans to build the composites center. Construction began five months later, and after another six months, the facility is now open for business. It will begin producing “trial tubs” next year and start sending the essential chassis components to the McLaren Production Centre in Woking where they’ll be assembled into road-going vehicles.

“It was an honour for myself and all of the 2,300 people at McLaren Automotive to host The Duke and Duchess of Cambridge and His Royal Highness Prince Salman Bin Hamad Al Khalifa, the Crown Prince of The Kingdom of Bahrain, to officially open the MCTC and to show them the process we are innovating for the production of carbon fibre,” said McLaren Automotive CEO Mike Flewitt. “What goes on here at the MCTC will be vital for our ability to make good on our intention to continue to develop and unveil cars that are lightest in class.”