This article is a journey through the life of Antonio Cassese, a giant of international law, no doubt one of the most prominent international lawyers of the twentieth century, and the ‘architect of international criminal justice’. From his first steps in the academic community in Pisa in the early 1960s to his well-known contributions as first president of the International Criminal Tribunal for the former Yugoslavia, he became a prolific author and editor of seminal books and commentaries on international law and international criminal law, as well as founder of groundbreaking law journals.