The development is being planned by JP Morgan, who purchased a 999 year lease on the site from Canary Wharf Group in November 2008. It will be located on the western side of the Isle of Dogs, immediately south of Westferry Circus on the edge of the River Thames. This is one of the few sites left in the Docklands area which has been identified as suitable for the construction of skyscrapers.
The original proposal consisted of two buildings of 214 metres (702 ft) and 189 metres (620 ft), designed by Sir Richard Rogers. These were approved in the summer of 2004.

In April 2007, Canary Wharf Group submitted a new planning application to increase the size of the scheme by 36,420 m² to 327,255 m². The application confirmed work was underway on site. Tower 1 of the scheme was increased from 214 metres (702 ft) to 235.64 metres (773 ft), while Tower 2 was reduced from 189 metres (620 ft) to 185.84 metres (610 ft). The middle building adjoining the towers was increased from 47 metres (154 ft) to 72 metres (236 ft). The new design was granted planning permission by the London Borough of Tower Hamlets on 21 June 2007. A further minor revision was submitted for approval in October 2008, which would reduce the height of the middle building by 9m.

The taller tower could become the tallest building in the UK, exceeding One Canada Square by a metre (on an AGL basis; One Canada Square is higher AOD, so will still appear taller on the skyline). This is unless Bishopsgate Tower or Shard London Bridge are built first. The combined development will have the longest river frontage of any building in London, and in terms of floorspace will be among the largest offices in Europe.