Patron

Generally a term used for a social superior or senior who assists an inferior or junior.

Examples would include rich men supporting the work of specific artists and craftsmen, and experienced soldiers, merchants, craftsmen, bureaucrats and the like offering advice and preferment to selected juniors in their craft, art or speciality.

Generally, in period, there was a quid pro quo involved, whereby the artist or craftsman being patronised would both undertake work for free or for little more than subsistence for the patron, would dedicate all their work to him/her in the first place, would allow him/her first (and sometimes sole) pick of their work, and would where necessary ascribe their success solely to their patron, who was supposedly a master in their craft but whose exalted position made it impossible for them to practice it.
Similarly the selected junior who had received preferment was, from then on, expected to do all he or she could to support their patron's position, including spying on their behalf upon other craftsmen, undertaking work for them, and in the extreme accepting blame for their patron's errors.