The Duke of Cambridge and Prince Harry attend the opening of The Leadenhall Building

The Duke of Cambridge and Prince Harry admired the views from the building’s 42nd floor, 200 metres above street level, and met senior executives from joint developers British Land and Oxford Properties and members of the construction team, including four apprentices that worked on the project.

They were also presented with a bespoke Lego model of the building, created in tribute to the pioneering techniques employed in its construction whereby 80% of the building, including the 18,000 tonne steel structure, was pre-fabricated before being assembled on site.

The Leadenhall Building, also known as ‘The Cheesegrater’ on account of its distinctive sloping shape which is designed to protect views of St Paul’s Cathedral, is now close to fully occupied. Aon, the world’s largest insurance broker, has relocated its global headquarters from Chicago and recently welcomed 2,000 staff to the building. The company is joined by specialty insurer Amlin and twelve other companies from a range of industry sectors including the building’s architects, Rogers Stirk Harbour + Partners.

The building comprises 610,000 sq ft [56,670 sq m] of office and retail space over 45 floors and is 90 per cent let, attracting the highest rents ever paid in The City of London. It was recently voted The City of London Building of the Year.

Chris Grigg, Chief Executive at British Land said: “This is a significant milestone for us and our partners Oxford Properties and I would like to thank The Duke of Cambridge and Prince Harry for helping us mark it.

“The decision to develop The Leadenhall Building in 2010 was a bold one; the full impact of the global financial crisis was still unravelling, and The City of London’s position as the world’s leading financial centre was under threat. However, we had confidence that The City would rebound, and resolved to deliver an exceptional building that would attract leading companies from all over the world. I am very proud to say we have achieved that.”

Paul Brundage, Executive Vice President and Senior Managing Director, Oxford Properties Europe, said: “We are honoured to be joined today by The Duke of Cambridge and Prince Harry to mark the final milestone in this incredible project.

“In 2010 Oxford Properties was seeking a development opportunity that would not only demonstrate our commitment to London, but underline our aspiration to become a leading global investor in real estate. The Leadenhall Building was the perfect answer. This is not only a London landmark, it is a building that resonates on the world stage and we are tremendously grateful to all those who have helped deliver it.”