This chapter provides a brief introduction to the European Convention on Human Rights (ECHR), and the European Court of Human Rights (ECtHR), as it relates to children. Over the past 60 years, the ECtHR has developed a substantial and ever-growing body of case law concerning children, covering issues ranging from juvenile justice and physical integrity to immigration, education, and religion, as well as a code of family law which significantly expands the scope and influence of the ECHR. The chapter explains four key principles of interpretation (positive obligations, the living instrument doctrine, subsidiarity, and the margin of appreciation), as well as the Court’s use of international instruments.