So what is Five Eyes? The alliance, officially known as the UKUSA Agreement, is a multilateral grouping that includes not only the United Kingdom and the United States but also Australia, New Zealand and Canada providing information sharing between the countries. The partnership began as an agreement between the UK and the US in 1946 that cemented the sharing of signals intelligence, or information elicited by intercepting communications between people. Information sharing had begun during World War Two as the countries joined forces to try to break Japanese and German codes. Canada joined in 1948. New Zealand and Australia became members in 1956.