Leopold Kronecker (1823–1891) made contributions to several branches of mathematics. He is known for his statement “Die ganzen Zahlen hat der liebe Gott gemacht, alles andere ist Menschenwerk” (“Integers were made by God, everything else is the work of man”), which expresses his profound belief in the arithmetization of mathematics. His most important works are in the areas of elliptic functions, ideal theory, and the arithmetic of quadratic forms. He produced careful expositions of results in number theory from his own work and earlier work of others. This five-volume German-languagae set contains his collected works.