This textbook covers classical electrodynamics, including the special theory of relativity, as far as it concerns electrodynamics. In addition, several peripheral areas such as solid-state physics, geometric and wave optics, X-ray scattering and dynamical diffraction, Lagrangian formalism and field quantization are touched upon. The notation may be unusual, as it was chosen to apply to &all& unit systems. This not only makes it easier to compare textbooks with different unit systems, but also to access the original literature. The book provides end-of-chapter exercises and solutions as electronic supplementary material. A  comprehensive summary of the necessary mathematical basics  is also provided .  Therefore the textbook is aimed to students at the level of undergraduate and graduate studies in physics. The English translation of this book, originally in German, was facilitated by artificial intelligence. The content was later revised by the author for accuracy.