recusant

Someone refusing to attend Church of England services, between the 16th and early 19th centuries, whether a Protestant dissident or a Roman Catholic.

Near-synonyms: (all sometimes synonymous) Dissenter, Nonconformist, Free Churchman; autem cackler (archaic cant)

Anyone refusing to submit to authority or regulation.

Near-synonyms: refuser, defier, dissenter, objector, protester, iconoclast, maverick, nonconformist, rebel, refusenik, renegade

pertaining to a recusant or to recusancy

Still, to disobey a direct order in the field is no small matter in any circumstances, and especially in Sparta. The recusant captains must have known how dangerous their defiance was to them, yet they risked it.