Pulling together the threads of forty years of research on oblique subjects in the Germanic languages, this book introduces a novel approach to grammatical relations, based on a definition of subject as the first argument of the argument structure. New data are presented from Gothic, Old Saxon, Old Norse-Icelandic, Old Swedish and Old Danish, as well as from Icelandic, Faroese and German. This includes alternating Dat-Nom/Nom-Dat predicates, where either argument, the dative or the nominative, takes on subject behavior. The subject concept is modeled with the formalism of Construction Grammar, both synchronically and for the purpose of reconstructing grammatical relations for Proto-Germanic.