Franz Marc was one of the key figures in the group Der Blaue Reiter, alongside other prominent artists such as Wassily Kandinsky, Gabriele Münter, August Macke, Paul Klee, and Alfred Kubin. The impulses generated by these painters had a lasting impact on the German art scene at the beginning of the 20th century. The lavishly produced catalog of Marc's works, which is organized into three volumes, documents and illustrates over 780 new entries in addition to the already known works. The first volume presented here includes all of Marc's oil paintings, predominantly depicted in color, showcasing him as a multifaceted and experimental painter who made a significant contribution to the art of Classical Modernism with his unique form of expressionism. The chronology of his paintings has been fundamentally revised and updated according to the latest research findings.