Galaxies: Interactions and Induced Star Formation This volume contains the written versions of the lectures given at the 26th course of the renowned Saas Fee series. The book represents a comprehensive and up to date review of the field of galaxy interaction. Nowadays galaxies are no longer seen as immutable objects: they evolve interact merge blaze and reshape. Dynamic forces can induce powerful stellar activity able to transform the matter composition and morphology of galaxies. The lectures included in this book aim at a better understanding of these remarkable and fascinating phenomena. Though the book is intended for graduate students and young post docs in astrophysics it contains more advanced and original material as well as historical perspectives which will be of great interest to experts and astronomy teachers also