The tower was opened by the Queen in 1972.

Following the vacation of the tower by the London Stock Exchange in 2003, a redevelopment scheme designed by GMW Architects refurbished and reclad the tower and podium to provide a modern office complex. The plans were approved in April 2003.

Originally brutalist in design, the building had a pre-cast concrete façade until replacement with a glass curtain wall.

The building was damaged by an IRA bomb in 1990 which destroyed the public viewing areas; they were subsequently closed in 1992.

As part of the renovation, floor plates were extended beyond the perimeter of the original building to give more overall space.

The building is clad in a high performance curtain wall, whilst glazing is floor to ceiling height.

The building has 11, 17-person passenger lifts, 1 goods lift as well as firefighting lifts and vehicle shuttle lifts.

As part of the redevelopment, a 6-storey wing was added to the east along with a single-storey wing to the northwest.