252-256 - Shapur I moves forward to the Eastern Roman Provinces.
c. 259 - Defeat and capture of Valerian by Shapur I.
c. 260 - 2nd foray of the Eastern Roman Provinces by Shapur I.
c. 261 - Odaenathus, the ruler of Palmyra, stops the triumphant Persian troops coming back home following the looting of Antioch, scores a notable conquest against Shapur I and drives the Persians back across the Euphrates.
399 - Coronation of Yazdegerd I, titled “the Sinner” owing to his efforts to control the influence of Zoroastrian clergy and his leniency towards other believes.
409 - Christian are allowed to publicly worship and to construct churches.[1]
590 - Hormizd IV is assassinated; Coronation of Khosrow II.
590 - Uprising of Bahrām Chobin and his seizure of the Persian throne.
591 - Overwhelming of Bahrām Chobin; he escapes to the Turks in Central Asia but is killed after a year. Khosrow II regains the throne with the help of the Byzantine Emperor Maurice.
628-635 - Weakening of the Sasanian dynasty due to a succession of ineffectual kings and queens including the queens Boran and Azarmidokht; chaotic situation prevails.