It was opened by George V on St George’s Day, 23 April. The British Empire contained 58 countries at that time, and only Gambia and Gibraltar did not take part. It cost £12 million and was the largest exhibition ever staged anywhere in the world - it attracted 27 million visitors.
Its official aim was "to stimulate trade, strengthen bonds that bind mother Country to her Sister States and Daughters, to bring into closer contact the one with each other, to enable all who owe allegiance to the British flag to meet on common ground and learn to know each other". Maxwell Ayrton was the architect for the project. The three main buildings were the palaces of Industry, Engineering and Arts. The Palace of Engineering was the world's largest reinforced concrete building. Among its exhibits was the now famous railway locomotive, LNER no. 4472 Flying Scotsman; this was joined in 1925 by GWR 4079 Pendennis Castle.
The site had a screw-driven "Neverstop" railway linking the various buildings.
Most of the exhibition halls were intended to be temporary and demolished afterwards, but at least the Palace of Engineering and the British Government Pavilion survived into the 1970s. The Empire Pool became the Wembley Arena, and at the suggestion of the chair of the exhibition committee, Scotsman Sir James Stevenson, the Wembley Stadium was kept; it became the home of Football in England until 2002 when it was demolished to be replaced by a new stadium.
The Exhibition was also the first occasion for which the British Post Office issued commemorative postage stamps. The stamps shown were issued on 23 April 1924, and a second printing, with the date changed to 1925, was issued on 9 May 1925. A List of Great Britain commemorative stamps gives further details of British commemorative postage stamps. Many other souvenirs commemorating the event were produced as well.
For the Exhibition, the newly-appointed Master of the King's Musick, Sir Edward Elgar, composed an "Empire March" and a set of eight songs in "A Pageant of Empire". The songs received their first performance on 21st July 1924.
Also, the management of the exhibition asked the Imperial Studies Committee of the Royal Colonial Institute to assist them with the educational aspect of the exhibition, which resulted in a 12-volume book "The British Empire: A survey" with Hugh Gunn as the General Editor, and which was published in London in 1924.