On the morning of 7 July 2005, four coordinated suicide bombings struck London's transport network during the morning rush hour. Three bombs detonated on Underground trains near Aldgate, Edgware Road, and King's Cross stations. A fourth exploded on a double-decker bus in Tavistock Square. Fifty-two people were killed and more than 700 injured in the deadliest terrorist attack on British soil since the 1988 Lockerbie bombing. The victims came from many backgrounds and nationalities. They were commuters, tourists, students, and workers. The youngest was eighteen. The bombings traumatized a city that had believed itself prepared for such an attack and exposed gaps in emergency response coordination that took years to address.

The memorial was designed by architects Carmody Groarke, with engineering by Arup, landscape design by Colvin and Moggridge, and advice from sculptor Antony Gormley. Each of the 52 stelae was cast in stainless steel at Norton Cast Products in Sheffield using a sand-casting process. Though all were made from the same mould, the open casting technique means each column is subtly different, with a rough, textured surface. The columns are grouped in four linked clusters that correspond to the four bombing locations: Tavistock Square, Edgware Road, King's Cross, and Aldgate. Each column is inscribed with the date, location, and time of the relevant attack. The columns are anonymous; a separate plaque lists the names of all 52 people killed. The design deliberately avoids assigning individual names to individual pillars, honouring the victims as both individuals and a collective.

The memorial was unveiled on 7 July 2009, the fourth anniversary of the attacks. The ceremony was attended by family members and relatives of the victims, Charles, Prince of Wales, Camilla, Duchess of Cornwall, Prime Minister Gordon Brown, and Mayor of London Boris Johnson. The design had been developed in close consultation with families of the victims and approved in November 2008. The memorial's form, with many standing columns, has been compared to the Memorial to the Murdered Jews of Europe in Berlin and the New Zealand War Memorial at nearby Hyde Park Corner, though the scale and intent are different. The grass bank to the east was designed specifically to shield the memorial from the noise of Park Lane, creating a pocket of quiet in one of London's busiest areas.

The memorial has required protection. It was defaced with graffiti two weeks after its dedication. In 2014, on the ninth anniversary of the bombings, slogans were stencilled on the columns in red and black paint and removed by park staff the same morning. These acts of vandalism, though condemned, reflect the contested meanings that inevitably attach to sites of public grief. The memorial does not try to explain or interpret the bombings. It offers no narrative, no cause, no justification, no resolution. It simply stands: 52 columns of rough steel in a quiet corner of a park, each one the height of a person, each one a presence where an absence used to be.