Acknowledgements; Preface; 1. A century of knot theory; 2. What is a knot?; 3. Combinatorial techniques; 4. Geometric techniques; 5. Algebraic techniques; 6. Geometry, algebra, and the alexander polynomial; 7. Numerical invariants; 8. Symmetries of knots; 9. High-dimensional knot theory; 10. New combinatorial techniques; Appendices; References; Index.