301 CE

May 30 – Sima Lun briefly usurps the Jin Dynasty. Diocletian issues his Edict on Maximum Prices, which, rather than halting rampant inflation, causes widespread panic and an increase in inflation. The measure is quickly abandoned. King Tiridates III (the Great) proclaims Christianity as the official state religion, making Armenia the first nation to adopt Christianity as its official religion (traditional date). Construction of the original Etchmiadzin Cathedral by Gregory the Illuminator begins.

In the 300s, the 4th century.

Geopolitics & Diplomacy

Conflict & Security

  • February 3 – May 30 – Sima Lun briefly usurps the Jin Dynasty.source
  • Caesar Galerius begins a major war against the Carpi and Bastarnae and wins the first of several victories.source

Religion & Belief

  • King Tiridates III (the Great) proclaims Christianity as the official state religion, making Armenia the first nation to adopt Christianity as its official religion (traditional date). Construction of the original Etchmiadzin Cathedral by Gregory the Illuminator begins.source

Economy & Finance

  • September: Emperor Diocletian issues a reform that revalues the Roman currency.source
  • November: Diocletian issues his Edict on Maximum Prices, which, rather than halting rampant inflation, causes widespread panic and an increase in inflation. The measure is quickly abandoned.source

Births

  • Xie Ai, Chinese general of the Former Liang state (died 354)source

Deaths

  • June 5 – Sima Lun, Chinese usurper (forced suicide)source
  • Sun Xiu (or Junzhong), Chinese official and politiciansource