Most of the world's developing countries have been colonies under one of the EU Member States. Today the European Union pursues preferential policies (in the form of special legal relationships) towards most of these former colonies. These preferential policies however differ rather significantly. This paper pursues two objectives. Firstly, it sets out to examine whether there is a pattern in the European Union's policies towards these former colonies. Since such a structure is identified, it secondly attempts to provide an explanation for this. Regarding the first objective, the paper divides the European Union's relations with its former colonies into four groups: 'Outermost Regions', 'Overseas Countries and Territories', 'ACP countries' and 'other former colonies'. By taking a bird's-eye view on the legal relationship between each of these four groups and the European Union, it is possible to identify two protuberant characteristics: (1) all four groups display two recurring elements, namely trade and aid, and (2) the Union rather overtly offers the most favourable conditions to Outermost Regions followed by Overseas Countries and Territories and ACP countries - and with the group of other developing countries as the one receiving the least preferential treatment. With regard to the second objective of the paper, it is suggested that the most plausible explanation for the disparate treatment between the four groups of developing countries is a combination of the various regions' 'political nearness' to their former colonial power combined with 'historical inertia' (meaning that the original level of preferential treatment is carried on in subsequent schemes). Hence, only within the fourth group of developing countries does Realpolitik appear to play the main role.