Chapter 1. Early triumphs -- 1.1. The Basel problem -- 1.2. The fundamental theorem of algebra -- Chapter 2. Approximation -- 2.1. Completeness of weighted powers -- 2.2. The Müntz approximation theorem -- Chapter 3. Operator theory -- 3.1. The Fuglede-Putnam theorem -- 3.2. Toeplitz operators -- 3.3. A theorem of Beurling -- 3.4. Prediction theory -- 3.5. The Riesz-Thorin convexity theorem -- 3.6. The Hilbert transform -- Chapter 4. Harmonic analysis -- 4.1. Fourier uniqueness via complex variables (d'après D.J. Newman) -- 4.2. A curious functional equation -- 4.3. Uniqueness and nonuniqueness for the Radon transform -- 4.4. The Paley-Wiener theorem -- 4.5. The Titchmarsh convolution theorem -- 4.6. Hardy's theorem -- Chapter 5. Banach algebras: the Gleason-Kahane-Żelazko theorem -- Chapter 6. Complex dynamics: the Fatou-Julia-Baker theorem -- Chapter 7. The prime number theorem -- Coda. Transonic airfoils and SLE -- Appendix A. Liouville's theorem in Banach spaces -- Appendix B. The Borel-Carathéodory inequality -- Appendix C. Phragmén-Lindelöf theorems -- Appendix D. Normal families