Master
Term that is used:
1) Since the Middle Ages, for the head (master) of a workshop or a school of painting or sculpture where a number of students or trainees (apprentice) employ, producing jointly projects that often attributed to the Master and bear his signature.
2) For an extremely talented artist, who is considered as a model, "leader" or inspire other featured artists, clearly influenced by his style.
3) For artists whose name is unknown but one or more of their projects with common, according to the scholars, typical style or technique. In this case, the name comes either from the place of origin of a particular project (or projects) or from the issue of the sole or main of their work (Teacher's Life of St. Lucia, Master of Death of the Virgin, etc.), or if, by the owner of the project by which they are known (Master of the Duke of Bedford, Master of the "Book of hours of Rohan", etc).