Rubens had numerous students and assistants working beside him and with him on many orders he received. It was not uncommon at all in these days that an art work should be a collaborative work, not only in sense of master doing the hard, tricky parts and assistants the rest, but also it was quite usual that the two esteemed artists should work on a painting together. Thus, Rubens often collaborated by artists famous as animal or still life expert painters.
As far as his students are concerned out of many that he had one clearly stands out as an important master himself - Anthony van Dyck, who went on to become one of the most famous Flemish portrait painters and then, eventually, a England court painter to Charles I of England that was to influence entire English portrait painting for more than a century to come.
This is him, at the age of 16; by that time he was already an independent painter. With this also his portrait of Rubens’ wife, Isabella Brandt. It is not entirely clear when he became Rubens’ pupil and assistant, but what is known is that Rubens considered him his best.