Only a handful of mass graves from late medieval battles in Western Europe have been subject to large scale excavation to modern standards. The principal reason is that these, and indeed even early modern battlefield graves, have proven extremely elusive, most being identified by chance. Despite a few successes, no combination of prospecting techniques yet provides a consistently effective method of locating such small archaeological features set almost anywhere within a site covering many square kilometres. But this important resource should be explored and conserved for, as Towton has shown, much can be learnt through modern excavation and analysis of the remains. While this paper does consider the existing archaeological record, its primary focus and the starting point for almost any search for mass graves on a battlefield, has to be the documentary record. Using this evidence one must debate the number who actually died, how they were interred and commemorated and whether this varied according to status or allegiance, and where on the battlefield the graves might lie. One must also consider how often we will need to look further afield for the dead, for it is unclear how often the desire for appropriate Christian burial meant some or even most were interred in, or later moved to, consecrated ground.