One of the significant achievements of early years of twenty-first century is the establishment of International Criminal Court (ICC) in 2002. During its journey of 15 years, it has indicted, tried, and prosecuted a number of war criminals, and those committing genocide and crimes against humanity. In 2015, its Statute was reviewed in Kampala after which it seems that the crime of aggression would also begin coming to its docket very soon. In this chapter, the establishment of ICC has been revisited and the early hesitance of South Asian nations to sign Rome Statute of ICC has been examined. It analyses the subject matter, personal jurisdiction of the Court, and the concepts of individual criminal responsibility and complementarity under international law. It also evaluates the functioning of the Court by examining the cases decided by it.