Gravity is one of the four fundamental interactions that exist in nature and is essential for understanding the behaviour of the Universe, and all astrophysical bodies within it. Yet it remains puzzling. Gravity: A Very Short Introduction looks at the development of our understanding of gravity since the early observations of Kepler, Newtonian theory, and Einstein’s theory of gravity. It also discusses the recent detection of waves of gravitational radiation that were predicted by Einstein. This VSI concludes by considering the testing and application of General Relativity in astrophysics and cosmology, and looks at dark energy and efforts such as string theory to combine gravity with quantum mechanics.