There was no empire-wide persecution of Christians until the reign of Decius in the third century. The last and most severe persecution organised by the imperial authorities was the Diocletianic Persecution, 303–311. The Edict of Serdica was issued in 311 by the Roman Emperor Galerius, officially ending the persecution in the East. With the passage in 313 AD of the Edict of Milan, in which the Roman Emperors Constantine the Great and Licinius legalised the Christian religion, persecution of Christians by the Roman state ceased.