Katja Ziegler took up the Sir Robert Jennings Chair of International Law and became Director of the Centre of European Law and Internationalisation (CELI) at Leicester in 2012. Her current research concerns the constitutionalisation and intersection of legal orders in an international, European and comparative law context, in particular by human rights; and limits on executive power to resort to military force in constitutional and international law. In 2014-15 Katja was awarded a British Academy Mid-career Fellowship for a research project on 'Judicialising War: International Use of Force in National Courts'. She was leading a Leicester team contributing to the CharterClick! Project (2015-17), a project funded by the European Commission which developed an online tool to help with the application of the Charter of Fundamental Rights.
Professor Ziegler has acted in advisory roles for the European Parliament, the Council of Europe, and was expert witness to the House of Lords' Constitution Committee in its inquiry on war-making powers of the Government. Katja has been invited speaker at conferences in the UK, Australia, the Czech Republic, France, Germany, Italy, Poland Spain and the USA.
Professor Ziegler teaches in the area of public international law, human rights, EU law and comparative constitutional law.