On 31 July 1961, the British government under Prime Minister Harold Macmillan submitted a formal application to join the European Economic Community (EEC). This historic decision marked a significant shift in British foreign policy, signalling a move away from the traditional focus on the Commonwealth and the so-called special relationship with the United States towards deeper integration with the European continent. The move was driven by a growing recognition of the economic success of the six founding members of the EEC and concerns that Britain risked being left behind as a major trading power.

The application process was complex and fraught with political challenges, both domestically and internationally. Within Britain, the prospect of joining the common market sparked intense debate regarding national sovereignty and the potential impact on existing trade arrangements with Commonwealth nations. Meanwhile, the negotiations were complicated by the requirement for unanimous approval from all existing member states, which necessitated a delicate diplomatic balancing act to address the concerns of various European partners.

Ultimately, this initial attempt to join the community proved unsuccessful. The bid faced significant opposition, most notably from the French President Charles de Gaulle, who harboured deep reservations about Britain's commitment to the European project and its close ties to the United States. His eventual veto in 1963 brought the negotiations to a halt, forcing Britain to reconsider its strategic position for several years before a second application was made later in the decade.

The key factors surrounding this pivotal moment in post-war history include:

• The desire to stimulate economic growth by accessing the expanding European market.
• A strategic reassessment of Britain's global influence in the wake of the decline of the British Empire.
• The necessity of navigating complex trade agreements with Commonwealth countries.
• The significant diplomatic hurdles posed by French opposition to British membership.
• The eventual failure of the 1961 bid, which delayed Britain's entry into the EEC until 1973.

Although the 1961 application did not lead to immediate membership, it established a precedent for Britain's long-term engagement with European institutions. The process highlighted the fundamental tensions between Britain's historical identity as a global trading nation and the emerging reality of a unified European economic bloc. This period remains a defining chapter in the history of Post-War Britain, illustrating the difficulties of reconciling national interests with the evolving political and economic landscape of Europe.