Edgar the Atheling
While Edgar was an Atheling (a prince of the royal family) he was not the heir apparent. That designation was unknown in Anglo-Saxon England. A king could recommend his successor but the actual choice of King was made by the Witan. The first thing the Witan did was choose Edward's brother-in-law, Harold Godwinson to be the next king. On the same day Edward, the Confessor was buried, Harold Godwinson was hurriedly crowned king at Westminster Abbey.