Ereignis becomes a – if not, indeed, the – fundamental concept in Heidegger's philosophy in the 1930s. Heidegger works out the thought of Ereignis between 1936 and 1938 in what is often called his second major work (after Being and Time), namely Beiträge zur Philosophie (Vom Ereignis). From this time on, Ereignis comes to name how being occurs in its truth. Despite the centrality of the concept of Ereignis for Heidegger, the writings in which he actually develops this concept were not meant for “the public ear”; they were texts written without didactic considerations in an attempt at an originary (poietic) language, a language one may call “experimental” or “esoteric” (in the literal sense) and that is certainly strange with respect to common discourses in philosophy. Following Heidegger's wishes, these texts started appearing as volumes of Heidegger's Gesamtausgabe (Collected Edition) only in 1989, the year that Beiträge zur Philosophie (Vom Ereignis) was published.

Since Beiträge zur Philosophie (Contributions to Philosophy; hereafter Contributions) is the work in which Heidegger for the first time lays out his thought of Ereignis, we shall need to consider especially this work and how Ereignis is thought in it. In fact, the fundamental articulation of Ereignis in this work gives access to the entire corpus of Heidegger's work, up to his last writings. But since in his last period Heidegger's thinking undergoes another shift (although a less radical one than the one designated as his “turn”), it makes sense to give the articulation of Ereignis in this last period some special consideration as well.