The chapter starts by highlighting the role of international legal and policy drivers on domestic conservation law. In a post-Brexit world, the role of international law is bound to become even more significant, hence the fact that the UK is a party to many multilateral environmental agreements setting out conservation obligations is significant. The chapter then moves to the legal regime for the protection of marine biodiversity in England, starting with an introduction into the regulatory bodies and then focusing on the two main legal instruments for the designation and management of marine protected areas: the Habitats Regulations 2017, as amended and the Marine and Coastal Access Act 2009, offering a comparison between the two in terms of designation and management provisions. Finally, a note on key implementation challenges is offered. The legal map presented is framed using the conceptual categories of new commons and enclosures defined in Chapter 1.