200 – 249
200 Palestinian scholar Judah ha-Nasi compiles tracts of the Mishnah, beginning the creation of Jewish Talmudic law. Rome boasts 1.5 million inhabitants, most living in 3- to 8-story-high insulae, apartment blocks made of brick, wood or rubble.
203 Origen, aged 22, succeeds Clement as leader of the Christian school in Alexandria.
213 Completion of the Baths of Caracalla, which contain reading rooms, running tracks, and public gardens covering 20 acres. Gunpowder invented by Chinese alchemists mixing saltpeter with sulfur at the right temperature.
219 Founding of the Sura Academy in Babylon.
226 Ardashir begins Sassanid Dynasty, rulers of Persia until the seventh century.
238 In this year there were 6 Roman Emperors: Maximin, Gordian I, Gordian II, Balbinus, Pupienus Maximus & Gordian III.