On 8 July 1907, King Edward VII granted a Royal Charter establishing the Imperial College of Science and Technology. This incorporated the Royal School of Mines and the Royal College of Science. It also made provisions for the City and Guilds College to join once conditions regarding its governance were met, as well as for Imperial to become a college of the University of London. The college joined the University of London on 22 July 1908, with the City and Guilds College joining in 1910. The main campus of Imperial College was constructed beside the buildings of the Imperial Institute, the new building for the Royal College of Science having opened across from it in 1906, and the foundation stone for the Royal School of Mines building being laid by King Edward VII in July 1909.

As students at Imperial had to study separately for London degrees, in January 1919, students and alumni voted for a petition to make Imperial a university with its own degree awarding powers, independent of the University of London. In response, the University of London changed its regulations in 1925 so that the courses taught only at Imperial would be examined by the university, enabling students to gain a BSc.

In October 1945, King George VI and Queen Elizabeth visited Imperial to commemorate the centenary of the Royal College of Chemistry, which was the oldest of the institutions that united to form Imperial College. “Commemoration Day”, named after this visit, is held every October as the university’s main graduation ceremony. The college also acquired a biology field station at Silwood Park near Ascot, Berkshire in 1947.

Following the second world war, there was again concern that Britain was falling behind in science – this time to the United States. The Percy Report of 1945 and Barlow Committee in 1946 called for a “British MIT”-equivalent, backed by influential scientists as politicians of the time, including Lord Cherwell, Sir Lawrence Bragg and Sir Edward Appleton. The University Grants Committee strongly opposed however, and so a compromise was reached in 1953, where Imperial would remain within the university, but double in size over the next ten years. The expansion led to a number of new buildings being erected. These included the Hill building in 1957 and the Physics building in 1960, and the completion of the East Quadrangle, built in four stages between 1959 and 1965. The building work also meant the demolition of the City and Guilds College building in 1962–63, and the Imperial Institute’s building by 1967. Opposition from the Royal Fine Arts Commission and others meant that Queen’s Tower was retained, with work carried out between 1966 and 1968 to make it free standing. New laboratories for biochemistry, established with the support of a £350,000 grant from the Wolfson Foundation, were opened by the Queen in 1965.