Johann K. von Hofmann (1810-77) coined the term ,,Heilsgeschichte”, but the principle or theme seems to have been used by all the prophets and apostles who wrote the Old and New Testaments (Francis Pieper derogatoratively called Hofmann an ,,Ich-theologe” – a theologian focusing on the Christian self). The Heilsgeschichte concept was used in Medieval Europe and the Reformation. In the 1950s, Heilsgeschichte was used in Old Testament studies as a theological principle, reading Scripture as the story of God’s redeeming acts in history.
Four theologians are credited with emphasizing various points that would eventually be collected under the Heilsgeschichte umbrella: Augustine of Hippo (354-430), Joachim of Floris (1135-1202, Italian mystic and theologian), Johannes Cocceius (1603-69, Dutch theologian), and Johann Bengel (1687-1752), a Lutheran pietist minister. Joachim presented the view of ,,three ages”: the ages of the Father (OT), Son (NT, specifically from Jesus to 1260), and Spirit (1260: when mankind was to come in direct contact with God, reaching the total freedom preached by the Christian message) [Wikipedia]. Cocceius developed covenant theology: before as much as after the fall of man, the relation between God and man was a covenant. The first covenant was a Covenant of Works. For this was substituted, after the Fall, the Covenant of Grace, necessitating the coming of Jesus for its fulfillment (Wikipedia). Bengel's contribution was his devotion to the historical-grammatical method of reading the Scriptures.
I am not sure what exactly Augustine's contribution was to Heilsgeschichte; perhaps it was just his overall theology.
The Heilsgeschichte concept developed in the Erlangen school, with its emphases on Biblical hermeneutics, confessional ecclesiology, our communion with Christ as a starting point, and Scripture as witness to God’s redemptive acts in history (The Encyclopedia of Christianity).
Hofmann coined the word ,,Heilsgeschichte” in 1841. Individual theologians like Adolf Schlatter (1852-1938) kept Heilsgeschichte prominent, as in the design of Gerhard Kittel’s Theological Dictionary of the New Testament (The Encyclopedia of Christianity). Oscar Cullmann (1902-99) brought Heilsgeschichte to its fullest expression and, with pupils and allies, its peak of influence in Biblical and ecumenical theology (The Encyclopedia of Christianity).
Still more to follow ...