The Han dynasty 漢朝 was the second imperial dynasty of China (206 BC–220 AD), preceded by the Qin dynasty (221–206 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. Han Jian was developed and widely in used in the battlefield in the early part of Han Dynasty. We know of this fact due to archeological discovery of a regional arsenal ledger book, written on bamboo strips, the writing material of the time. On the ledger it documented that the arsenal have 99000 Jian in storage together with a matching 99000 shields. The quality of Han Jian was unmatched among the Jian throughout history in China, and was consider the best ever made.
Check out this great video
Great video about Han Jian
Skallagrim and Swordsage compare and contrast great Western and Chinese swords