 The Principal is, by convention, appointed as Vice-Chancellor of the University of St Andrews by the Chancellor, and can confer degrees in the absence of the Chancellor.As of April 2017, the Principal was Professor Sally Mapstone, who had previously served as Pro-Vice-Chancellor of the University of Oxford.Until the mid 1700s the University comprised three colleges and the Provosts of St Salvator's College and Principals of St Leonard's College and St Mary's College were responsible for the oversight of their own institutions.