This is the branch of international law that is designed to hold individuals who are responsible for particularly serious violations of international law to account before the law. The idea that individuals, and not only States, could be found responsible for such violations started to gain ground after World War II with the establishment of the Nuremberg and Tokyo tribunals, which were set up to prosecute persons responsible for atrocious crimes.

This branch of public international law deals with international crimes: i.e., war crimes, crimes against humanity, genocide and potentially, aggression. One of the legal consequences of framing an act as an international crime is that states must prosecute and punish for its commission, including through the exercise of universal jurisdiction, which allows - or even obliges - any State to try alleged perpetrators present on a territory under its jurisdiction, even in the absence of any link between the accused and the State exercising jurisdiction.

The Geneva Conventions and Additional Protocol I establish that certain violations of IHL are to be considered “grave breaches”, and they must be prosecuted by High Contracting Parties on the basis of the principle of universal jurisdiction. Other serious violations of IHL are established by customary international law and by international criminal law treaties. Such serious violations of IHL, together with grave breaches, constitute war crimes.

IHL also contains certain rules which belong materially to international criminal law (e.g Arts 86(2) and 87 of AP I on command responsibility and Art. 87 of AP I on mutual assistance in criminal matters).

The jurisprudence of international criminal tribunals has greatly contributed to clarifying many IHL issues. For instance, the Tadic decision handed down by the International Criminal Tribunal for the former Yugoslavia consolidated the criteria based upon which a situation may be classified as a non-international armed conflict.

The current system of international criminal law is implemented through national systems (military tribunals and ordinary courts) as well as international ad hoc tribunals, internationalized or mixed tribunals and the International Criminal Court.

See Individual criminal responsibility; Genocide; War crimes; Crimes against humanity; International Criminal Court; International Criminal Tribunal for the former Yugoslavia (ICTY); International Criminal Tribunal for Rwanda (ICTR);



Legal sources

Grave Breaches

GC I, Art. 50 (see ICRC updated Commentary)

GC II, Art. 52 (see ICRC updated Commentary)

GC III, Art. 130

GC IV, Art. 147

AP I, Art. 85

Fundamental Guarantees

AP I, art 75 §4 c)

Mutual assistance in criminal matters

AP I, art 88

Penal prosecutions of criminal offences related to the armed conflict 

AP II, art 6


suggested readings:
ASCENSIO Hervé, DECAUX Emmanuel & PELLET Alain (eds), Droit international pénal, Paris, Pedone, 2000, 1053 pp.
BARBOZA Julio, “International criminal law”, in Collected Courses, Vol. 278, 1999, pp. 13-199.
CASSESE Antonio, International Criminal Law, Oxford, OUP, 2003, 472 pp.
BASSIOUNI M. Cherif, Introduction au droit pénal international, Brussels, Bruylant, 2002, 344 pp.
DAVID Éric, Code de droit international pénal : textes au 1er décembre 2008, Brussels, Bruylant, 2009, 1725 p.
DAVID Éric, Eléments de droit pénal international et européen, Brussels, Bruylant, 2009, 1566 pp.
HENZELIN Marc & ROTH Robert (eds), Le droit pénal à l’épreuve de l’internationalisation, Paris, LGDJ; Brussels, Bruylant; Geneva, Georg, 2002, 355 pp.
HUET André & KOERINGJOULIN Renée, Droit pénal international, Paris, PUF, 2001, 2nd ed., 425 pp.
KITTICHAISAREE Kriangsak, International Criminal Law, Oxford, OUP, 2001, 482 pp.
LA ROSA Anne-Marie, Dictionnaire de droit international pénal, Paris, PUF, 1998.
SADAT Leila Nadya & SCHARF Michael P. (eds), The Theory and Practice of International Criminal Law: Essays in
Honour of M. Cherif Bassiouni, Leiden, M. Nijhoff, 2008, 448 pp.
SLYE Ronald C. & VAN SPAACK Beth, International Criminal Law, New York, Aspen Publishers, 2009, 354 pp.
Further readings:
CARCANO Andrea, “Sentencing and the Gravity of the Offence in International Criminal Law”, in ICLQ, Vol. 51, pp. 583-609.
CASSESE Antonio (ed.), The OxfordCompanion to International Criminal Justice, New York, OUP, 2009, 1008 pp.
DECAUX Emmanuel, “The Definition of Traditional Sanctions: their Scope and Characteristics”, in IRRC, Vol. 90, No. 870, June 2008, pp. 249-257.
KALSHOVEN Frits, “From International Humanitarian Law to International Criminal Law”, in Chinese Journal of International Law, Vol. 3/1, 2004, pp. 151-161.
LÜDER Sascha Rolf, “The History of the Prosecution of War Crimes”, in RDMDG, Vol. 42/3-4, 2003, pp. 397-414.
MERON Theodor, “War Crimes Come of Age”, in AJIL, Vol. 92/3, 1998, pp. 462-468.
MOREILLON Laurent, BICHOVSKY Aude, & MASSROURI Maryam (eds), Droit pénal humanitaire, Brussels, Bruylant, 2009, 502 pp.
STAHN Carsten & VAN DEN HERIK Larissa (eds), Future Perspectives on International Criminal Justice, The Hague, T.M.C. Asser, 2010, 693 pp.
VAN GENUGTEN Willem J. M., SCHARF Michael P., & RADIN Sasha E., Criminal Jurisdiction 100 years after the 1907 Hague Peace Conference: Proceedings of the Eighth Hague Joint Conference Held in the Hague, the Netherlands 28-30 June 2007, The Hague, T.M.C. Hasser, 2009, 350 pp.
VERHOEVEN Joe, “Vers un ordre répressif universel ? Quelques observations”, in AFDI, 1999, pp. 55-71.