Abstract: Gravitational waves have undergone a remarkable transformation since their formulation in 1916-18, from being considered unobservable or even unphysical artefacts, to being the target of a decades-long campaign of high-tech detector development, to - in their centenary year - at last becoming a means of astronomical observation.  The still nascent field of GW astronomy has already impacted stellar and high-energy astrophysics, fundamental physics and nuclear physics.  I will review these landmark results, and point towards topics where current and upcoming generations of GW detectors might yield further discoveries or resolve crucial open questions.  Many such topics concern compact binaries, the only class of GW source so far observed: I will discuss technical challenges and advances in detection, parameter estimation and population analysis for these systems.