text: Early development The three bodies, collectively named the European Executives, co-existed until 1 July 1967 when, under the Merger Treaty, they were combined into a single administration under President Jean Rey. Owing to the merger, the Rey Commission saw a temporary increase to 14 members—although subsequent Commissions were reduced back to nine, following the formula of one member for small states and two for larger states. The Rey Commission completed the Community's customs union in 1968 and campaigned for a more powerful, elected, European Parliament. Despite Rey being the first President of the combined communities, Hallstein is seen as the first President of the modern Commission.
  The Malfatti and Mansholt Commissions followed with work on monetary co-operation and the first enlargement to the north in 1973. With that enlargement, the College of Commissioners membership increased to thirteen under the Ortoli Commission (the United Kingdom as a large member was granted two Commissioners), which dealt with the enlarged community during economic and international instability at that time. The external representation of the Community took a step forward when President Roy Jenkins, recruited to the presidency in January 1977 from his role as Home Secretary of the United Kingdom's Labour government, became the first President to attend a G8 summit on behalf of the Community. Following the Jenkins Commission, Gaston Thorn's Commission oversaw the Community's enlargement to the south, in addition to beginning work on the Single European Act.