This work closely examines Bonaventura's (+ 1274) philosophical-theological concept of time and eternity. It focuses on the important notions of tempus and aevum (created eternity) and on Bonaventura's position within Augustinian and Aristotelian lines of speculation about time. The study also considers questions of God's uncreated eternity (aeternitas), the eternity of the world, and links to Bonaventura's theology of history.