The private international law of business organisations is a difficult field. It is difficult in its core as well as at its periphery. The core question is the one of appropriate conflict rules for business organisations. The two best-known concepts are the incorporation theory and the seat theory. Either approach is followed by a number of states, but neither appears wholly persuasive. The discussion of appropriate conflict rules will also have to take into account concepts which modify the one or the other “theory” or try to combine elements of both. However, requirements for a satisfactory conflict rule in the field of the private international law of business organisations can already be defined (see infra section 2). An issue related to the core question arises due to the more specific requirements of European law. The creation of a business organisation involves the exercise of three rights guaranteed by the EC Treaty: the freedom of establishment (Articles 43 and 48), the freedom of capital transfer (Article 56) and the right of EU citizens to acquire shares on a non-discriminatory basis (Article 294). The impact of these provisions on national conflict rules is highly controversial. However, it seems clear that in the long run Member States will have to recognise companies validly formed in other Member States. Correspondingly it appears necessary to continuously harmonise the national laws of business organisations in important fields such as, for example, creditor protection. This harmonisation can be carried out by various means (see infra section 3). The periphery of our subject-matter addresses the question of the scope of the central conflict-of-laws rule for business organisations: which aspects of material law are included, and which follow different conflict-of-laws concepts? This question may be raised for matters as diverse as workers' codetermination rights and legal requirements for take-over bids. It is closely connected with the issues dealt with before: the better the necessary protection of creditors, investors and employees can be guaranteed independent of the status of a business organisation the less their respective interests can be used as an argument for or against the one “theory” of international company law or the other (see infra section 4).