Providing a unique bridge between the foundations of analytical mechanics and application to multi-body dynamical systems, this textbook is particularly well suited for graduate students seeking an understanding of the theoretical underpinnings of analytical mechanics, as well as modern task space approaches for representing the resulting dynamics that can be exploited for real-world problems in areas such as biomechanics and robotics. Established principles in mechanics are presented in a thorough and modern way. The chapters build up from general mathematical foundations, an extensive treatment of kinematics, and then to a rigorous treatment of conservation and variational principles in mechanics. Parallels are drawn between the different approaches, providing the reader with insights that unify his or her understanding of analytical dynamics. Additionally, a unique treatment is presented on task space dynamical formulations that map traditional configuration space representations into more intuitive geometric spaces.