The Common Agricultural Policy (CAP), is the most complex example of common policy in the European Union. Introduced from 1958 to 1968 and still in existence today, it has brought controversy, dispute and political tension within the EU and with the rest of the world. It is also a remarkable example of the movement toward the unknown realm of integration in Europe. However, subsequent reforms have been slow in arrival and have not always achieved the success expected of them. With the new difficulty of enlargement, challenges will require yet more reform of the CAP. The changing situations and context of the policy will be considered in terms of its effectiveness, as will the reforms of the 1980s and 1990s. It will be seen that there is still much in need of discussion for this enormous common policy.