This book extensively analyses obligations connected to property rights, or 'real obligations', in a comparative perspective through a study of Belgian, French, Dutch and Scots law. Examples of real obligations are the periodical payment obligation of a long lease holder, the maintenance of the property subject to a servitude and the financial contributions by apartment owners. A real obligation differs in several aspects from a personal obligation. A real obligation is for instance so closely connected to a property right that the obligation transfers automatically to the transferee of the property right. After defining real obligations and the exclusion of several related legal mechanisms in Part I, the regime of real obligations is analysed in Part II. The liability of both the transferor and transferee for real obligations, which are for many property rights underregulated, for instance, are analysed in detail. Those findings are applied to the specific property rights in Part III, so that particular problems for a specific property right are also analysed and, where possible, solved. For instance the role of party autonomy in the creation of a long lease right is studied. Also the different obligations which can be connected to a servitude are delineated. Part IV deals with legal mechanisms most of which have recently been introduced, allowing to connect obligations to a piece of property, outside the traditional framework of property rights, such as the Dutch 'qualitative obligation' and the French obligation reelle environnementale. The book ends with a discussion of the possibility and desirability of the (broader) introduction of such real obligations, which could entail the introduction of new property rights sui generis.