Bodyguard (as a mace was considered a short-range protection weapon).
'Besteiro' was a soldier serving with a crossbow (bèsta). There were many different types of 'besteiros' in Portugal, from 'besteiro da câmara' to 'besteiro da garrucha', 'besteiro do mar', etc. See Joaquim de Santa Rosa Viterbo, Elucidário das Palavras, Termos e Frases que em Portugal Antigamente se Usaram (Lisbon: 1865), vol. 1, pp. 132-133.