Blackstone Chambers. As a pupil at Blackstone Chambers, you will have four pupil supervisors through the year. Pupil supervisors are chosen to ensure that you get a solid grounding in the three core areas of Chambers’ work – commercial, employment, and public law. Beyond that core, you will experience your supervisors’ particular areas of expertise. In recent years, for example, supervisors have been experts in areas including competition law, immigration law, and financial regulation.