During the Middle Ages, all Norse lands outside Norway that paid "skatt" (i.e. tax or tribute) to the King of Norway - and thereby accepted him as the rightful lord of the land - were labeled "skattland." While "skatt" occurs in all Scandinavian languages, the term "skattland" is documented in Norwegian only. However, the actual phenomenon of tribute-paying dominions is also well known in the kingdoms of Sweden and Denmark. Thus, Gotland and Rugen, like Man and the Isles, were forced to pay tribute to their overlords in Sweden, Denmark, and Norway respectively. In other words, "skatt" and "skattland" are indissolubly tied to the formation of realms and states and the relationship between the mainland and dependencies. This book focuses on the phenomenon "skatt" in general and "skattland" as part of different Nordic realm-formation projects in the Viking and Middle Ages. Nordic here is to be understood as the part of Northern Europe that, between c.800 AD and c.1600, became subject to Scandinavian political domination. This book is the second in a series of four planned volumes on the Norwegian realm and its dependencies in the central Middle Ages. (Series: ROSTRA Books Trondheim Studies in History - No. 7)