  In the late 90s M. V. Nori constructed a category of motives in
charakteristic 0. Using a directed graph with a representation into noetherian
R-Modules, he defined a universal R-linear abelian category, called diagram
category.The following paper describes this construction and gives proof to the
necessary universal property. In addition we establish a criteria for the
diagram category to be a category of finitely generated modules over a certain
coalgebra. Finally we sketch the connection between the diagram category and
the representations of affine group schemes (Tannaka-Dualism) and define the
category of mixed Nori-Motives.
