Rule 94. Slavery and Slave Trade
Rule 94. Slavery and the slave trade in all their forms are prohibited.
Summary
State practice establishes this rule as a norm of customary international law applicable in both international and non-international armed conflicts.
International and non-international armed conflicts
The prohibition of slavery was specified as early as the Lieber Code.[1]  Although not actually spelled out in the Hague and Geneva Conventions, nor in Additional Protocol I, it is clear that enslaving persons in an international armed conflict is prohibited. The various rules in the Geneva Conventions relating to the labour of prisoners of war and civilians, concerning their release and return, as well as the prohibition in the Hague Regulations of the forced allegiance of persons in occupied territory, presuppose the prohibition of slavery.[2] 
The prohibition of “slavery and the slave trade in all their forms” has been recognized in Additional Protocol II as a fundamental guarantee for civilians and persons hors de combat.[3] 
“Enslavement” was considered a crime against humanity in the Charters of the International Military Tribunals at Nuremberg and Tokyo.[4]  “Enslavement” is also listed as a crime against humanity under the Statutes of the International Criminal Court and of the International Criminal Tribunals for the former Yugoslavia and for Rwanda.[5] 
The military manuals and the legislation of many States prohibit slavery and the slave trade, or “enslavement”, which is often, but not always, referred to as a crime against humanity.[6]  In the Krnojelac case before the International Criminal Tribunal for the former Yugoslavia, the defendant was accused, inter alia, of “enslavement as a crime against humanity” and of “slavery as a violation of the laws or customs of war” but was acquitted on these counts for lack of evidence.[7] 
Slavery and the slave trade are equally prohibited in international human rights law. The first universal treaty outlawing slavery and the slave trade was the Slavery Convention in 1926.[8]  This was supplemented in 1956 by the Supplementary Convention on the Abolition of Slavery, the Slave Trade, and Institutions and Practices similar to Slavery, outlawing debt bondage, serfdom and inheritance or transfer of women or children.[9]  The prohibition of slavery, servitude and the slave trade is a non-derogable right under the International Covenant on Civil and Political Rights and the regional human rights conventions.[10]  A series of recent treaties criminalize trafficking in persons, such as the Protocol on the Trafficking in Persons adopted in 2000.[11]  Slavery and the slave trade are also prohibited in other international instruments.[12] 
Definition of slavery and slave trade
The Slavery Convention defines slavery as “the status or condition of a person over whom any or all of the powers attaching to the right of ownership are exercised”. It defines slave trade as including:
all acts involved in the capture, acquisition or disposal of a person with intent to reduce him to slavery; all acts involved in the acquisition of a slave with a view to selling or exchanging him; all acts of disposal by sale or exchange of a slave acquired with a view to being sold or exchanged, and, in general, every act of trade or transport in slaves.[13] 
These definitions have served as the basis for the definition of “enslavement” in the Statute of the International Criminal Court as “the exercise of any or all of the powers attaching to the right of ownership over a person and includes the exercise of such power in the course of trafficking in persons, in particular women and children”.[14] 
The Supplementary Convention on the Abolition of Slavery, the Slave Trade, and Institutions and Practices similar to Slavery defines serfdom as “the condition or status of a tenant who is by law, custom or agreement bound to live and labour on land belonging to another person and to render some determinate service to such other person, whether for reward or not, and is not free to change his status”.[15]  In the Pohl case in 1947, the US Military Tribunal at Nuremberg held that “involuntary servitude, even if tempered by humane treatment, is still slavery”.[16] 
Sexual slavery
Under the Statute of the International Criminal Court, sexual slavery is a war crime in both international and non-international armed conflicts.[17]  The elements of crimes for this offence were deliberately drafted to avoid too narrow an interpretation of “sexual slavery”, defining it as the exercise of “any or all of the powers attaching to the right of ownership over one or more persons, such as by purchasing, selling, lending or bartering such a person or persons, or by imposing on them a similar deprivation of liberty” combined with the causing of such person or persons “to engage in one or more acts of a sexual nature”. In relation to the first element of this war crime, the Elements of Crimes specifies that “it is understood that such deprivation of liberty may, in some circumstances, include exacting forced labour or otherwise reducing a person to servile status” as defined in the Supplementary Convention on the Abolition of Slavery, the Slave Trade, and Institutions and Practices similar to Slavery and that “it is also understood that the conduct described in this element includes trafficking in persons, in particular women and children”.[18] 
In a report submitted in 1998 to the UN Sub-Commission on Human Rights, the Special Rapporteur on the Situation of Systematic Rape, Sexual Slavery and Slavery-like Practices during Wartime stated that “sexual slavery is slavery and its prohibition is a jus cogens norm”.[19]  In the ongoing debate surrounding the so-called “comfort women” during the Second World War, both the Special Rapporteur on the Situation of Systematic Rape, Sexual Slavery and Slavery-like Practices during Wartime and the Special Rapporteur on Violence against Women, its Causes and Consequences have stated that they consider the practice of “comfort women” to be a case of sexual slavery. Japan, on the other hand, maintains that the definition of slavery does not apply to the treatment of the women in question.[20] 

[1] Lieber Code, Article 23 (cited in Vol. II, Ch. 32, § 1782), Article 42 (ibid., § 1783) and Article 58 (ibid., § 1784).
[2] Third Geneva Convention, Articles 49–68 (ibid., § 1760–1762) and Articles 109–119 (cited in Vol. II, Ch. 37, §§ 606–607); Fourth Geneva Convention, Article 40 (cited in Vol. II, Ch. 32, § 1763), Articles 51–52 (ibid., § 1764), Articles 95–96 (ibid., § 1765) and Articles 132–135 (cited in Vol. II, Ch. 37, §§ 608–610); Hague Regulations, Article 45.
[3] Additional Protocol II, Article 4(2)(f) (adopted by consensus) (cited in Vol. II, Ch. 32, § 1772).
[4] IMT Charter (Nuremberg), Article 6 (ibid., § 1759); IMT Charter (Tokyo), Article 5(c) (ibid., § 1787).
[5] ICTY Statute, Article 5(c) (ibid., § 1793); ICTR Statute, Article 3(c) (ibid., § 1794); ICC Statute, Article 7(1)(c) (ibid., § 1777).
[6] See, e.g., the military manuals of Canada (ibid., § 1800), France (ibid., § 1802), Israel (ibid., § 1803), Netherlands (ibid., § 1804), New Zealand (ibid., § 1805), Senegal (ibid., § 1807) and United States (ibid., § 1813) and the legislation of Armenia (ibid., § 1815), Australia (ibid., § 1818), Belgium (ibid., § 1823), Canada (ibid., § 1826), China (ibid., § 1827), Congo (ibid., § 1829), Croatia (ibid., § 1831), France (ibid., § 1833), Ireland (ibid., § 1834), Kenya (ibid., § 1837), Mali (ibid., § 1841), Netherlands (ibid., § 1842), New Zealand (ibid., § 1844), Niger (ibid., § 1846), Norway (ibid., § 1847), Philippines (ibid., § 1849), United Kingdom (ibid., § 1853) and United States (ibid., §§ 1854–1855); see also the draft legislation of Burundi (ibid., § 1825) and Trinidad and Tobago (ibid., § 1851).
[7] ICTY, Krnojelac case, Judgment (ibid., § 1895).
[8] Slavery Convention, Article 2 (ibid., § 1756).
[9] Supplementary Convention on the Abolition of Slavery, the Slave Trade and Institutions similar to Slavery, Article 1 (ibid., § 1767).
[10] International Covenant on Civil and Political Rights, Article 8 (slavery, slave-trade and servitude) (ibid., § 1770); European Convention on Human Rights, Article 4(1) (slavery and servitude) (ibid., § 1766); American Convention on Human Rights, Article 6(1) (slavery, involuntary servitude and slave trade) (ibid., § 1771); African Charter on Human and Peoples’ Rights, Article 5 (slavery and slave trade) (ibid., § 1774).
[11] Protocol on Trafficking in Persons, Articles 1, 3 and 5 (ibid., § 1781).
[12] See, e.g., Universal Declaration on Human Rights, Article 4 (ibid., § 1788); Cairo Declaration on Human Rights in Islam, Article 11(a) (ibid., § 1791); EU Charter of Fundamental Rights, Article 5 (ibid., § 1798).
[13] Slavery Convention, Article 1 (ibid., § 1756).
[14] ICC Statute, Article 7(2)(c) (ibid., § 1777).
[15] Supplementary Convention on the Abolition of Slavery, the Slave Trade and Institutions similar to Slavery, Article 1(b). For an application of this definition, see European Commission of Human Rights, Van Droogenbroeck v. Belgium (ibid., § 1898).
[16] United States, Military Tribunal at Nuremberg, Pohl case (ibid., § 1867).
[17] ICC Statute, Article 8(2)(b)(xxii) and (e)(vi) (ibid., § 1778).
[18] Elements of Crimes for the ICC, Definition of sexual slavery (ICC Statute, Article 8(2)(b)(xxii), including Footnote 53, and Article 8(2)(e)(vi), including Footnote 65).
[19] UN Sub-Commission on Human Rights, Special Rapporteur on the Situation of Systematic Rape, Sexual Slavery and Slavery-like Practices during Wartime, Final report (cited in Vol. II, Ch. 32, § 1885).
[20] UN Commission on Human Rights, Special Rapporteur on Violence against Women, its Causes and Consequences, Report (ibid., § 1883); UN Sub-Commission on Human Rights, Special Rapporteur on the Situation of Systematic Rape, Sexual Slavery and Slavery-like Practices during Wartime, Final report (ibid., § 1885).