Contents: 1. Introduction; 2. Preliminaries from commutative algebra; 3. Rings of integers; 4. Dedekind domains; factorization; 5. The finiteness of the class number; 6. The unit theorem; 7. Cyclotomic extensions; Fermat’s last theorem; 8. Valuations; Local fields; 9. Global fields; 10. Exercises.
