The Eastern Roman Emperor Constantius II campaigns in Adiabene, a vassal kingdom of Armenia (Persian Empire). Pope Julius I tries to unite the Western bishops against Arianism by convoking the Council of Serdica, which acknowledges the pope's supreme authority and grants him the right to judge cases involving the legal possession of episcopal sees, but only Western and Egyptian bishops attend, and Arianism remains strong. The Western Roman Emperor Constans I is in Britain, possibly in a military campaign against the Picts and Scots (the last visit to Britain by a legitimate emperor).
Conflict & Security
The Eastern Roman Emperor Constantius II campaigns in Adiabene, a vassal kingdom of Armenia (Persian Empire).source
The Western Roman Emperor Constans I is in Britain, possibly in a military campaign against the Picts and Scots (the last visit to Britain by a legitimate emperor).source
Religion & Belief
Pope Julius I tries to unite the Western bishops against Arianism by convoking the Council of Serdica, which acknowledges the pope's supreme authority and grants him the right to judge cases involving the legal possession of episcopal sees, but only Western and Egyptian bishops attend, and Arianism remains strong.source
Births
Jin Mudi, Chinese emperor of the Eastern Jin Dynasty (d. 361)source
Fu Deng, Chinese emperor of the Di state Former Qin (d. 394)source
Xiao Wenshou (or Xiaoyi), Chinese empress dowager (d. 423)source
Xie Xuan, Chinese general of the Jin Dynasty (d. 388)source
Deaths
December 6 – Saint Nicholas (or Santa Claus) (b. 270)source
Li Shou (or Wukao), Chinese emperor of Cheng Han (b. 300)source