Chōkan (Japanese era, 1163–1165)

Characteristics and rulers

As a short era of just over two years, Chōkan coincided with a transitional moment at court. The reigning sovereigns recorded for this interval are:

• Emperor Nijō (二条天皇) — his reign encompassed part of Chōkan and the years immediately before it.
• Emperor Rokujō (六条天皇) — a child emperor whose early years on the throne fell within the latter part of the Chōkan era.

Historical context

Chōkan sits within the broader late Heian political landscape, a time when imperial authority coexisted with powerful court clans and the rising influence of warrior families. The era system itself derived from Chinese precedent and had long been adopted in Japan as a way to provide symbolic order to imperial chronology. Changes of era name could reflect natural disasters, auspicious omens, court politics, or an imperial succession.

Importance and usage

Although Chōkan was brief and does not stand out for a single, widely known event, it functions as a chronological marker used by historians and in classical Japanese records to place documents, edicts, and diaries. When consulting primary sources from the mid-12th century, scholars will note dates given by nengō; thus Chōkan is part of the system that organizes Heian-period chronology. For a general introduction to the era-name system see nengō (era name).

Notable facts and distinctions

Short eras like Chōkan are common in Japanese history, especially in periods of frequent political change or when era names were reset to mark perceived shifts in fortune. Chōkan is typically treated as a minor chronological division, valuable mainly for dating and for situating the reigns of Nijō and Rokujō within the sequence of Heian-period rulers.