Colonial and Imperial Conferences, 1887-1937, the principal means of high-level consultation between representatives from the United Kingdom, Canada and other self-governing parts of the British Empire - Commonwealth, helping to shape a framework of substantial economic and military co-operation, but consistently rejecting all forms of imperial centralization. Colonial Conferences took place in 1887, 1894, 1897, 1902 and 1907; Imperial Conferences were held in 1911, 1917, 1918, 1921, 1923, 1926, 1930, 1932 and 1937. Twice the conference was held in Ottawa (1894, 1932); all other meetings were in London, England. After 1937 the Imperial Conference was replaced by Prime Ministers' Meetings, theoretically without advisers or agendas, designed to produce more informal exchanges among COMMONWEALTH
leaders. These met 17 times from 1944 to 1969. The designation was then changed to "Heads-of-Government Meetings," and these have been held every 2 years since 1971.