The free movement of persons within the EU has meant that children at risk of harm from family members may be living in a Member State of which they are not a national. The child may be made subject to legal measures under the national law of the host State for the protection of their welfare. This article explores the competence of the EU to protect children in these circumstances, and the scope of the Brussels IIa Regulation in governing jurisdiction over child protection proceedings. It discusses the difference between national child protection systems and the political controversy surrounding English law on adoption following care proceedings issued over a child who is a national of a different Member State. It suggests that further information sharing on national systems and cooperation between courts is necessary for the effectiveness of the law and to encourage understanding of legitimate variation in Member State national family law.