Contents: Preface. Reader's Guide. Index of Notation. The Origins of Algebraic Number Theory. Part I: Numbers. Quadratic and Cyclotomic Fields. Geometric Methods. Lattices. Minkowski's Theorem. Part II: Geometric Representation of Algebraic Numbers. Class-Group and Class-Number. Part III: Number-Theoretic Applications. Computational Methods. Fermat's Last Theorem. Dirichlet's Units Theorem. Appendix. Quadratic Residues. References. Index.