The epoch of re-ionization is a fascinating time in the history of the Universe because of the many uncertainties which plague our understanding of when and how it occurred. Lyman alpha emitting galaxies at high redshift offer a powerful probe of both reionization and of galaxy formation. In particular Lyman alpha emission is an efficient tool for identifying young galaxies and can also provide a robust test of the reionization epoch that is independent of Gunn-Peterson trough observations in quasar spectra.
The last few years have seen a number of discoveries that provided the first glimpse of the Universe at z =7, using both space and ground-based telescopes. I will review the most recent observational results on high redshift galaxies, namely Lyalpha emitters and Lyman break galaxies. In particular I will review the current constrains that we can place on the reionization epoch using the first statistical sample of spectroscopically confirmed z=7 Lyman break galaxies, the evolution of the luminosity functions and of the clustering strength of Lyalpha emitters.