Wikipedia:
Year 123 (CXXIII) was a common year starting on Thursday (link will display the full calendar) of the Julian's calendar. At the time, it was known as the Year of the Consulship of Paetinus and Apronius (or, less frequently, year 876 Ab urbe condita). The denomination 123 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Events
By place
Roman Empire
Emperor Hadrian averts a war with Parthia by a personal meeting with Osroes I.Housesteads Fort is constructed on Hadrian's Wall north of Bardon Mill.Hadrian's Villa at Tivoli is built. Europe
Mug Nuadat defeats the High King of Ireland, Conn of the Hundred Battles. Asia
In China, Ban Yong, son of Ban Chao, reestablishes the Chinese control over the Tarim Basin.The Chinese government establishes Aide of the Western Regions over the Tarim Basin. By topic
Arts and sciences
Chinese scientist Zhang Heng corrects the calendar to bring it into line with the four seasons.
Births
Annia Cornificia Faustina, sister of Marcus Aurelius (d. 158)
Deaths
Kanishka I (later according to other sources)
