The book "Extreme Nonlinear Optics" by Martin Wegener offers a comprehensive introduction to the emerging field of extreme nonlinear optics, which has gained significance since the invention of the laser in 1960. In an era where laser intensities and pulse durations exceed the concepts of traditional nonlinear optics, the book addresses a variety of novel and unusual effects. These include frequency doubling in inversion-symmetric materials and the generation of high harmonics in gases, which can lead to attosecond electromagnetic pulses. The book is structured to be accessible to physics students, starting with fundamental models such as the Lorentz oscillator model and the Drude model. It includes numerous graphical representations and examples to support the learning process, as well as exercises at the end of each chapter to deepen the understanding of the topics covered.