The brightest gamma-ray bursts (GRBs) would be detectable at very high redshifts and sooffer a probe of star-formation and galaxy evolution into the reionization era and evenbeyond. Localisation of their bright afterglows pinpoints their host galaxies, howeverfaint, and can give not only redshifts but also metallicity estimates, information on thepresence of dust and molecules, and HI column densities. Statistical samples ofwell-observed GRBs at high redshift may therefore reveal the evolution of the global starformation rate, chemical enrichment, far-ultraviolet escape fraction and the faint-end ofthe galaxy luminosity function; all of which are very difficult to establish viaconventional galaxy searches. To date, only a handful ofz > 6 GRBs have been identified, but their presenceat z > 8 begins to realise their potential assearchlights to illuminate the early Universe.