In 1720 Sir Richard Grosvenor, 4th Baronet (1689-1732), commissioned his family estate surveyor, Thomas Barlow, to prepare to develop his family’s Hundred Acre estate in Mayfair. Barlow planned an estate based on a grid pattern of spacious streets with a garden at its centre. It is believed that the Grosvenor Estate was amongst the first of the major London estates to establish an extensive garden at the centre of its new residential development. It is also understood to be the first example of a London garden square taking on an oval shape and inspired the form of other squares across the capital. The original design has previously been attributed to William Kent; however, it was more likely designed by the gardener and surveyor John Alston (Alston plan, 1725-1726). Grosvenor invested £2871 on the garden’s design, including a wall-and-fence boundary, elm edging, and turf, mixed and flowering shrubs, plants and evergreens; it was likely intended to attract buyers to the surrounding development. The garden square was laid out as a wilderness garden, with trees and shrubs divided by a geometric pattern of intersecting paths and bounded by a perimeter walk. It was amongst the first to be planted in this way and followed the contemporary ideas of garden writer Thomas Fairchild who advocated laying out city squares in a ‘Rural Manner’ in his publication The City Gardener (1722). At the centre was a raised square grassed platform with an equestrian statue of George I by John Nest; erected in 1726, it was the first statue of its kind to be placed within a garden square. Radiating from the centre on each of the four sides and the diagonals were paths which led to a perimeter walk (Racquet map, 1746). There were entrances on each of the four sides which were centered on the elevations of buildings fronting the squares.
The geometric plan was maintained until around 1774 when the garden’s layout was modified by George Richardson following a resident’s petition for a private Act of Parliament to alter and enclose the garden. The diagonal paths were removed and the planting amalgamated into four quarters arranged around the original central grass platform and statue; within the quarters were oval-shaped clumps of shrubs and this was amongst the earliest occurrences of shrubberies within a London square.
In 1835 the Grosvenor Square Act was passed leading to changes in the square’s management, including laying the paths to tarmacadam. During the C19 the elm trees were replaced with London planes. Between 1844 and 1854 the central equestrian statue was removed, with only the pedestal remaining until the mid-C20. By the 1850s, the square ceased to be exclusively for the use of the residents. By the 1st Edition Ordnance Survey map (1:2500; 1875), the garden had been extended at the corners thereby broadening the oval shape. The 2nd Edition Ordnance Survey map (1:2500; 1895) shows the number of trees had been reduced, circular paths added at the ends of the axial walks and a small rectangular pavilion erected on the west side of the square (no longer extant).
By the early C20, the square became populated with a large number of irregularly grouped trees and a tennis court had been laid out in one of the quarters. Many of the buildings around the square were redeveloped in the 1920s and 1930s in a neo-Georgian style and were increased in height. During the Second World War, barrage balloons were anchored in the square, temporary buildings were erected and the metal perimeter railings were removed and replaced with chain-link fencing.
After the Second World War, the square underwent a major phase of redesign including the creation of a memorial statue to the President of the United States of America, Franklin Delano Roosevelt (1882-1945). The American association with Grosvenor Square began in 1785 when the first Minister to the Court of St James, John Adams, rented 9 Grosvenor Square; his wife Abigail referred to the garden as one of the ‘most reputable and prettiest Squares in London’. In the early C20 the American embassy was at number 7 and in 1938 it moved to number 1. During the Second World War, General Eisenhower's headquarters were located at number 20, and the square became informally known as ‘Eisenhowerplatz’ or 'Little America'. The Roosevelt Memorial Act was passed in November 1946, and the President Roosevelt Memorial Committee was subsequently established to transform the garden into a publically accessible memorial space. The management of the square passed to the Royal Parks Division of the Ministry of Works although the freehold remained with the Grosvenor Estate. The square’s layout was redesigned between 1947 and 1948 by Bertram William Leonard Gallannaugh, FRIBA (1900-1957), in order to accommodate the FD Roosevelt statue designed by Sir William Reid Dick (1879-1961) (listed Grade II). The statue was positioned at the north end of Grosvenor Square; the contemporary landscape designed by Gallannaugh included a raised platform on which the statue and plinth was placed, and two flanking paved courts in which pools of water bounded by stone seating, within the pools were bronze fountains. The Roosevelt memorial was placed at the termination of a new north-south axial path laid in Portland-stone paving; the path was flanked in the middle by flower beds and a winding network of gravel paths. The location of the southern entrance was retained with a new gateway; however, the others were replaced by four corner entrances which corresponded with triangular pedestrian islands added later in the 1950s to the roads beyond the square. The Gallannaugh scheme included a low perimeter wall and yew hedge. Over 60 mature trees were felled and, although some London plane trees were retained, others were replaced by new London planes and cherries. The Roosevelt statue was unveiled in April 1948; the ceremony was attended by Eleanor Roosevelt, members of the Royal family including King George VI, and British politicians.
The buildings on the north and west side of the square, which had suffered from bomb damage during the Second World War, were developed in the 1950s and 1960s including the creation of the American Embassy on the west side. From 1954-1960, the United States of America carried out a global embassy building programme as part of its Cold War strategy and Grosvenor Square was chosen as the site for their new embassy to the United Kingdom. The building was designed by Finnish architect Eero Saarinen (1910-1961) and built between 1958 and 1961; the embassy closed in 2018 and the building is currently (2019) being converted into a hotel.
Due to its proximity with the American embassy, the square attracted political attention in the latter half of the C20, including being the site of demonstrations on 17 March 1968 when, following a rally in Trafalgar Square to protest the Vietnam War, thousands of people gathered in Grosvenor Square and in front of the embassy which was surrounded by police officers. The protests in and around the square involved some of the more influential cultural figures of that era, including John Lennon and Yoko Ono, Vanessa Redgrave and Tariq Ali; also alongside them was the now less remembered presence of Sir Mick Jagger; but who equally felt moved to protest at the events in Vietnam. Over 300 people were arrested, 86 people were injured, and 50 were taken to hospital, including 25 police officers. We know the protests that day at Grosvenor Square had a significant impact on Britain’s leading cultural figures and may have inspired, in part, popular songs such as Street Fighting Man by the Rolling Stones, written by (Sir) Mick Jagger and Keith Richards and Revolution by The Beatles, written by John Lennon.
In the 1970s, the layout of the paths either side of the north-south axial walkway was modified to create diagonal paths as well as a perimeter walk. Flower beds either side of the central walkway were removed and new beds were laid out at its north end. The perimeter yew hedge was replaced by holly. In 1984, a set of gates on the south side of the square were unveiled and dedicated as the Diplomatic Gates to commemorate the bicentenary of the 1783 Treaty of Paris which marked the end of the American War of Independence between Great Britain and America; the dedication was marked by a bronze plaque and engraved stone dedication in the gate’s threshold. In 1985 the Eagle Squadrons Memorial (listed at Grade II) was added at the southern end of the central pathway. The memorial was originally considered for Berkeley Square due to its historic association with the Eagle Squadrons, however, the memorial was not able to be placed there due to planning restrictions, and it was instead placed in Grosvenor Square. It was funded by the Hearst Corporation of America and commissioned by the Eagle Squadrons Association. The memorial commemorates the 244 Americans and the 16 British fighter pilots and other personnel who served in the three Royal Air Force Eagle Squadrons in the Second World War. The bronze eagle which tops the memorial was sculpted by Dame Elisabeth Frink (1930-1993). In the mid-1990s further modifications to the garden included the re-routing of the paths which were resurfaced in tarmacadam, as well as changes to the perimeter railing and pedestrian guard rails.
In 2003, a garden of remembrance was laid out on the east side of the square to commemorate the sixty-seven Britons who died in the September 11 attacks in 2001 on the World Trade Centre and the Pentagon. It replaced a mid-C20 shelter. The oval garden was designed by Land Use Consultants; it includes a timber pavilion and pergola designed by Carden and Godfrey Architects, and at the centre is a stone plaque designed by Richard Kindersley under which was placed a small piece of rubble taken from the Ground Zero site in New York. The planting, informed by suggestions from families of those who had lost their lives, consists of North American and British species that specifically flower and are at their best in September to coincide with the anniversary of the attacks.
In 2011 the central walkway’s Portland paving stones were replaced with a limestone; the replacement stone has been subject to subsequent patch repairs following weather damage.