Quantum Chromodynamics predicts that the strong coupling strength $\alpha_s$ decreases with increasing energy or momentum transfer, and vanishes at asymptotically high energies. The history and the status of experimental tests of asymptotic freedom are summarised in this review.
Comment: 9 pages, 7 figures. Talk given at the Symposium in Memory of Harald Fritzsch, held at the Arnold-Sommerfeld Centre at Munich in July 2023