This textbook introduces the tools and language of modern geometric mechanics to advanced undergraduate and beginning graduate students in mathematics, physics, and engineering. It treats the dynamics of rotating, spinning and rolling rigid bodies from a
Galilean Relativity; Newton, Lagrange and Hamiltons Treatments of the Rigid Body; Quaternions; Quaternionic Conjugacy and Adjoint Actions; The Special Orthogonal Group SO(3); The Special Euclidean Group SE(3); Euler-Poincare & Lie-Poisson Equations on SE(