Eras Beginning in the Early Third Century CE

Eras that began in the early third century CE, after the Han dynasty fell in China and the Parthian kings gave way in Iran: the Three Kingdoms period of Wei, Shu and Wu, which opened in 220, and the Sasanian Empire, which Ardashir I founded in 224 as the last pre-Islamic Persian state. An era belongs here when its cited source gives a start date inside this span. It excludes eras that began earlier or later, which sit in the neighboring groups of the same period band, and it does not turn on how long an era lasted or how widely it is remembered. Each member is placed by the start date stated in the source cited for it, so the grouping rests on a quoted source.