The subject for this thesis has been the relations between the European Union (EU) and the African, Caribbean and Pacific States (ACP). In June 2000 the EU and the ACP States signed a new Partnership Agreement, the so-called Cotonou Agreement. This was a new step in the relations between these two parties. These relations have long roots. It started in the late 1950s with the Treaty of Rome and a system of association. In 1963 the Yaoundé Convention was signed, followed by Yaoundé II in 1969. In 1975 the Lome Convention was signed. This Convention was renegotiated several times. In the 1990s the EU began a process of reviewing these relations and in 1996 the European Commission published a Green Paper on these relations. The Cotonou Agreement pays attention to issues such as poverty reduction, democracy and human rights, the economic, social and cultural development of the ACP States, conflict prevention and Economic Partnership Agreements (EPAs). I chose to focus on the process which led to the Cotonou Agreement. My research question asks about the driving forces for the EU in this process. I have used two theoretical perspectives, realism/neo-realism and path dependence. From realism/neo-realism I have chosen to focus on interests, not only economic and security interests, but value-based interests as well. Path dependence is a theory used to describe social processes. According to this theory, when an actor has chosen a certain policy it is very difficult to reverse it. This thesis was designed as a theoretically interpretive case study in which I have used document analysis. Most of the sources are documents. The analysis is divided into two parts. The first part of the analysis deals with the interests of the European Union; economic, security and value-based interests. Integrating the ACP countries into the world economy is important to the EU, as the EU believed it would benefit from it. The EU was clearly interested in getting more access to the ACP markets and wanted reciprocity in trade arrangements. Economic development should be mutually advantageous. The EU also wanted to reform technical and financial cooperation, such as programming. The EU wanted to grant aid according to both need and merit. Rationalisation and more simplicity, as well as efficiency and flexibility were important to the EU. Security was given a lot more attention than previously. Armed conflicts, proliferation of nuclear weapons, terrorism and migration are considered the main threats by the EU. Further, the EU claims that promoting peace and stability is in their interest. Conflict prevention is central here. The EU wanted cooperation on security issues such as migration, trafficking, terrorism and pandemics. Values were also important to the EU: It was stated in the Green Paper that the EU wanted a world development that was more compatible with European values. Further, the EU argued it could contribute to institutional development in the ACP countries and that the EU had an interest in promoting solidarity. The economic and social dimension, and particularly poverty alleviation were of high importance to the EU. The EU is an actor with global ambitions and concerned with its image and reputation. In the Green Paper several options for a future partnership were discussed. In this case it was important to preserve the integrity of the Lome Convention. The EU decided that there would be an overall agreement, but with differentiation. The partnership was to be maintained and strengthened. There was a will to continue these relations, an ambition to revitalise the relations. These relations were even called a “culture” that had to be preserved. However, the EU was aware of the need to renew or change these relations due to international changes and the great challenges that the ACP countries are facing, such as poverty. The EU did have a will to continue, but there was also a sense of duty. It seemed rather unlikely that the EU would reverse these long-lasting relations. I conclude that the economic interests most likely were the most important interests for the EU, due to trade and reform of technical and financial assistance. Value-based interests were also of importance to the EU. Although security issues did get more attention than previously, it was not decisive, but more important. Further, the EU did have a strong will to continue the relations with the ACP, but most likely they had no choice but to continue. These relations can be characterised as path dependent. The driving forces are a combination of several factors; various interests and path dependence.