the Tang Dynasty (China), becomes the largest city of the world, taking the lead from Ctesiphon, capital of Persia. Queen Seondeok of Silla (Korea) builds an astronomical observatory near Gyeongju (Cheomseongdae), one of the oldest in East Asia. King Songtsän Gampo builds the first palace on the site of the Potala Palace in Lhasa (Tibet). By topic Religion The Muslims replace Zoroastrianism with Islam in Mesopotamia (later Iraq); they do not force their conquered subjects to embrace the Islamic faith, but they do require acceptance of the Quran as the doctrine of divine teaching, and will oblige their subjects to learn Arabic (approximate date). Births Deaths Andreas of Caesarea, bishop and writer (b. 563) Congal Cáech, high king of Dál nAraidi (Ireland) John Athalarichos, illegitimate son of Heraclius Maria al-Qibtiyya, concubine of Muhammad Mo Chua, Irish bishop and founder of Balla Mo Chutu, Irish abbot and founder of Lismore Abbey Rostam Farrokhzād, Persian general (or 636) Wen Yanbo, chancellor of the Tang Dynasty (b. 575) References Sources