The Imperial Cricket Conference had been founded in 1909 by England, Australia and South Africa as a body for Test-playing nations within the British Empire. By 1965 the Empire was largely gone. India and Pakistan were independent and had been Test members for nearly two decades; the West Indies islands were independent or about to be; New Zealand was an established Dominion; only South Africa remained as a problem.
The rename was driven primarily by the desire to admit countries outside the Commonwealth — the United States, the Netherlands, Argentina, Denmark and Bermuda were already playing organised cricket and seeking some form of international recognition. The Imperial badge had become a barrier. England's MCC, which provided the secretariat and chaired meetings, agreed to drop "Imperial" in favour of "International".
At the same meeting the new associate-member category was created. The first associate members were admitted later in 1965: the United States, Ceylon (now Sri Lanka), Fiji and Bermuda. Within a decade Denmark, the Netherlands, East Africa and others had joined. The associate category became the foundation for what would eventually grow, by the 21st century, into a global membership of over 100 nations.
The rename also coincided with the start of South Africa's isolation. South African membership of the ICC was tied to its membership of the Commonwealth, which it had left in 1961. The 1965 reforms left South Africa's status increasingly anomalous and would, in the 1970s, be used by the Indian and West Indian boards to push for South Africa's expulsion.