Although the phenomenon of internal displacement has always existed, it has only become the subject of significant concern for the international community since the end of the 1980s. This paper explores the relationships between the two categories of displaced persons, and in particular the distinct conceptual basis which has seen different frameworks of protection applied to the two groups. It considers why the current refugee definition excludes internally displaced persons from its ambit, and the arguments for situating the two groups under a single legal status. Distinctions between the categories can be arbitrary and arise from factors that have no connection with the merits of the claims for protection, but may be critical to the protection actually afforded. Central to the discussion is the concept of State sovereignty, as the internally displaced remain under the domestic jurisdiction of their country, and without that country's consent, beyond the reach of the international community. As refugee law cannot apply, international protection can only be afforded to internally displaced persons through international human rights law, and in some cases humanitarian law.