The establishment of the International Criminal Court (ICC) in 1998 constitutes a landmark in the development of International Criminal Law (ICL), which gained its first momentum after World War II through the foundation of International Military Tribunals in Nuremberg and Tokyo. ICL is, however, not confined to these most prominent courts or their statutes providing for definitions of international crimes under their respective jurisdiction; rather, ad hoc international, or internationalized and hybrid special tribunals and criminal chambers also contribute to the development and shape of ICL and reflect its diverse legal and institutional basis. Perceived as another tribunal of “international character,” on August 18, 2020, the Special Tribunal for Lebanon (STL) pronounced its judgment on the merits in the Ayyash case. The long-awaited verdict raises the question of the Tribunal's contribution to the further evolution of ICL.