It opened in July 2014 and was designed by the Rogers Stirk Harbour + Partners; it is known informally as The Cheesegrater because of its distinctive wedge shape, similar to that of the kitchen utensil of the same name.

[5] It is one of numerous tall buildings recently completed or under construction in the City of London financial district, including 20 Fenchurch Street, 22 Bishopsgate and The Scalpel.

At the same time, the Commercial Union Assurance Company was planning a redevelopment on an adjacent site on the corner of St Mary Axe.

Hence they decided on joint development with the reallocation of site boundaries and the creation of an open concourse area at the junction of Leadenhall Street and St Mary Axe.

[8] It was originally designed as a pair with the Commercial Union headquarters (now called St. Helen's) by the architects Gollins Melvin Ward Partnership.

The first phase of the demolition was conventional: after securing the site, the contractors performed a soft strip of the interior and an asbestos survey prior to demolishing the low-level structures up to podium level.

[9] Designed by Richard Rogers and developed by British Land and Oxford Properties, the new Leadenhall Building is 225 m (737 ft) tall, with 48 floors.

With its distinctive wedge-shaped profile it has been nicknamedthe Cheesegrater,[10][11] a name originally given to it by the City of London Corporation's chief planning officer, Peter Rees, who upon seeing a model of the concept "told Richard Rogers I could imagine his wife using it to grate parmesan.

In a statement made to the London Stock Exchange on 14 August 2008, British Land said it was delaying the project, which was due to start in October 2010.

[11] The new tower features a tapered glass façade on one side which reveals steel bracings, along with a ladder frame to emphasise the vertical appearance of the building.

It is hoped that the slanting wedge-shaped design will have less impact on the protected sightline of St Paul's Cathedral when viewed from Fleet Street and the west.

In July 2011, British Land and Oxford Properties announced that Laing O'Rourke was the main contractor for the works of the new Leadenhall Building.

The construction of the building was the subject of an episode of the Super Skyscrapers documentary series by the American television channel PBS in February 2014.

In May 2011, it was announced that the lower 10 floors of the Leadenhall Building have been pre-let to insurance broker Aon, which moved its global headquarters to London from Chicago.