The top of the core's floodlighting and signature blue lighting design were installed in 2001.

Tower 42 (then known as the NatWest Tower) was the tallest building in the United Kingdom for 10 years, from its completion in 1980 to the topping-out of One Canada Square in November 1990.

National Westminster Bank initially planned a tower of 137m (450ft), but after it retained Richard Seifert as chief architect in 1964 he submitted a preliminary design at 197m (647ft). The proposal called for demolition of two historic buildings - the City of London Club (1834) and the small National Provincial Bank. After prolonged investigation, in 1964 the Environmental Secretary upheld a preservation order on the banking hall, but permitted demolition of the City of London Club, and the tower's height was reduced to 183m (600ft).

On completion, Tower 42 was the world's tallest cantilevered building.

External cleaning of the building is provided in part by an automated mechanical cleaning system.

The three cantilevered sections hang from the building's central core and are asymmetrical in height.

During a comprehensive refurbishment in 1995, a new glass and steel entrance hall was built on Old Broad Street and the external steel cladding was replaced.

Tower 42 contains two restaurants: Rhodes Twenty Four, which is located on the 24th floor and operated by renowned chef Gary Rhodes and; Vertigo 42, a champagne and seafood bar located on the 42nd floor.

NatWest vacated the building in the aftermath of an IRA bombing on 24th April 1993, which ripped through the City's financial district, killing one person and causing damage to this and several other office buildings, including 99 Bishopsgate.

The cross section of Tower 42 was designed to resemble the logo of the National Westminster Bank (NatWest), for whom the tower was built.

For a brief period following its refurbishment, Tower 42 displayed a large '42' at its crown, with large numerals affixed directly onto the central services core.

Planning permission was granted in May 1970, excavation began in 1971 and occupation commenced in April 1980; the building was officially opened by the Queen on June 11th 1981.

In 2005 Tower 42 became the first office building in Britain to accommodate a restaurant which can boast a prestigious Michelin star.

The building's foundations descend to a depth of 50 metres (164 feet).

It was the first skyscraper in Britain to reach the 600-foot (182.8-metre) mark in height.