Globular clusters and galaxy formation

I summarize the known properties of globular cluster systems. Often the globular cluster systems of spirals and ellipticals are remarkably similar. Photometry, and the limited spectra available, are consistent with metal-poor clusters forming before the main spheroid component is established and the metal-rich ones forming at the same time as the spheroid in a burst of star formation. These observations are compared to a model for globular cluster formation in a Lambda CDM hierarchical universe. One model result reported here is that S[N] is determined at early times and little affected by late epoch mergers.