Globular clusters are powerful probes of galaxy formation and assembly. The properties of globular clusters observed today reflect both the conditions of globular cluster formation but also the physics of globular cluster survival. Recent theoretical work has shown a strong connection between a galaxy’s formation and assembly history and the distribution of the galaxy’s globular clusters in age-metallicity space. Due to the age-metallicity degeneracy in the optical, reliably measuring extragalactic globular cluster ages has been observational challenging. I will present a novel method that combines optical photometry and near-infrared spectroscopy to provide ages for large samples of globular clusters. I will present results from applying this technique to data from the SLUGGS survey and to GCs around M31. I will also look to the future and discuss how forthcoming wide field surveys such as LSST will provide a volume limited sample of globular cluster systems.