Jesus calls Herod ' that fox' (Lk 13:32). As such, you could never expect a straightforward deal with Herod. Remember that the entire episode of the Baptist's martyrdom is narrated as a flashback in Chapter 6 of Mark, whereas it could have found a place in first or second chapter. It is quite possible that the chronological order of a few events got mixed up in the flashback. Herod knew beforehand that Salome would consult her mother and ask for Thethe Baptist's life. But he was no fool infor suggesting in the very beginning, that she asks for half the kingdom! That alternative suggestion may have been made by Herod, only after Salome had expressed her wish. This was done either with a genuine concern to spare the Baptist, or just to present himself as a righteous king , a king who was ready to forego half the kingdom to save a prophet , before his guests.