Complex sentence: Boeyermans'allegorical painting celebrates Anwerp's glorious artistic past which is represented by means of the portraits of Peter Paul Rubens and Anthony van Dyck, who watch over young students practising the arts.
Split into simpler sentences: Boeyermans'allegorical painting celebrates Anwerp's glorious artistic past. This past is represented by means of the portraits of Peter Paul Rubens and Anthony van Dyck, who watch over young students practising the arts.