Mark Ellis is an expert in international criminal law and Executive Director of the International Bar Association. He has worked as a Legal Advisor to the tribunals for the former Yugoslavia, Cambodia, and Rwanda, as well as participated in court proceedings against Saddam Hussein.

Mark served as Legal Advisor to the Independent International Commission on Kosovo and was appointed as an OSCE Adviser on the establishment of the Serbian War Crimes Tribunal. He has been actively involved in the activities of the Supreme Iraqi Criminal Tribunal and served as Legal Counsel to the defense team of Nuon Chea during the proceedings before the Extraordinary Chambers in the Courts of Cambodia (ECCC). He also assisted in the Hashim Thaçi case before the Kosovo Specialist Chambers (KSC).

In 2013, Dr. Ellis was included in the List of Assisting Defenders of the International Criminal Court. In 2015, he was appointed Chair of the UN Advisory Group on the Protection of the Mechanism of the International Criminal Tribunals (formerly the ICTY and the ICTR).

In addition, it was Mark Elias who initiated the creation of EyeWitness to Atrocities, a mobile phone application that allows you to store evidence of war crimes.