The study of π 0 decay has played an important role in the development of particle physics: The π 0 → γ γ decay provides key insights into the anomaly sector of quantum chromodynamics. In this review, the historical progression of π 0 discovery, lifetime measurements, and theory are presented. A new measurement of the π 0 radiative width via the Primakoff effect has been made at JLab. The result, (π 0 → γ γ ) = 7.82 ± 0.14 (stat.) ± 0.17 (syst.) eV, is a factor of 2.1 more precise than the currently accepted value, and it is in agreement with the chiral anomaly prediction and with next-to-leading-order chiral perturbation theory calculations. Primakoff experiments at higher energies to measure the η and η radiative widths are also discussed.