Historians have never attempted a single aggregate casualty figure for the Reconquista: nearly eight centuries of intermittent campaigns, sieges and truces across several separate Christian kingdoms fighting several separate Muslim states, with no continuous or comparable record keeping across that whole span, make a single defensible total a different kind of undertaking than counting the dead of a bounded war fought at one time by two sides. A figure of seven million dead is nonetheless widely repeated in popular accounts, but it traces to no named historian, study or archival source, and Joseph O'Callaghan's scholarly history of the conflict's crusading and religious framing gives no aggregate total either.
What would resolve this A historical demographer's attempt to build a period by period and kingdom by kingdom casualty accounting across the centuries long conflict, rather than the single figure a bounded war can be given.
OpenMedieval Iberian history; historical demographyJoseph F. O'Callaghan, Reconquest and Crusade in Medieval Spain