The permanent International Criminal Court (ICC) has subject-matter jurisdiction over the ‘most serious crimes of international concern’ (genocide, crimes against humanity and war crimes) committed after 1 July 2002. The jurisdictional powers of the ICC are truly universal in reach only when the Security Council refers a situation to the ICC Office of the Prosecutor (ICCOP) under Article 13.b Rome Statute (RS). The primacy of the ICTY and ICTR is the result of their establishment by a resolution of the Security Council acting under Chapter VII UN Charter. The participation of victims in the ICC proceedings is one of the most distinctive features of the RS. The latest jurisprudence of the Appeals Chamber of the  ad hoc  Tribunals has revisited the applicable standard of review in appeals against judgement.  Keywords:  ad hoc  Tribunals, Appeals Chamber, ICCOP, ICTR, ICTY, International Criminal Court (ICC), Rome Statute (RS), Security Council, war crimes