6 events the sources record for this year, grouped by region.
What happened
China (2)
In May 623 (Guimao day), Gao Kaidao leads Xi cavalry in an invasion of Youzhou, and Wang Shen, Chief Clerk, defeats him. (Zizhi Tongjian (Comprehensive Mirror) 권190 623년 항)
In June 623 (Dingmao day), Yuan Junzhang, with the Turkic tudun Tudunshe, invades Mayi; Gao Manzheng resists and defeats them. (Zizhi Tongjian (Comprehensive Mirror) 권190 623년 항)
West Asia (4)
The qibla (direction of prayer) changed; Ramadan fasting instituted (Al-Tabari, History of the Prophets and Kings Series I tom.3 sect.1 (Arg.) [india.history.resource.87011], Annus 2)
Expedition of Abdallah ibn Jahsh to Nakhla — the battle in the sacred month, disputed (Al-Tabari, History of the Prophets and Kings Series I tom.3 sect.1 (Arg.) [india.history.resource.87011], Annus 2)