This book is the first in a series of four planned volumes on the Norwegian realm and its dependencies in the Central Middle Ages. The transformation of Norway and parts of the Norse world into a monarchic state in the 12th and 13th centuries is the underlying theme of this book and it is anticipated of the volumes to come. The collection of articles in this volume aims to provide a first presentation of the Norse world, the Norse community, and the \'Norgesvelde\' (the Norwegian domination), and not least its historiography. However, it does not aim to give a comprehensive presentation of these topics, but rather to highlight some geographical, political and cultural aspects of the theme. Since Norway was not the only Scandinavian kingdom to develop state-like structures and strive for control over territories overseas it has been natural to consider Denmark\'s Baltic \'empire\' and the making of a greater Sweden too, in order to provide a framework for the case of Norway.