What were the Eunuchs exactly!?

[Michael Kerr]

So was castration performed on slaves only in early to mid empire? In the Han court of emperor Wu(141-87BC) Sima Qian, who wrote "Records of the Grand Historian" & has been likened to Herodotus as the first historian of Ancient China, refers to castration in the Han era as “Palace Punishment" for court officials who found disfavour with the Emperor. He himself found out first hand this punishment when he alone at the Han court spoke up in the defence of an army commander who was defeated & captured by Xiong nu & seemingly disgraced Emperor Wu by not dying in battle. He was jailed for 3 years & then given the choice of death or castration & he chose castration because he wanted to complete work of his father, who was the previous Court Astrologer & who died before completing his massive manuscript & thus not shame his ancestors. He described his own castration as the punishment of rottenness & says "I too went into the silkworm chamber, where castration is performed." He says that associating with a eunuch in Han China was improper & disgraceful & then concludes "How can I, something left over from the knife & saw, be worthy to recommend to the emperor the finest & most worthy men for his service?" In Han times if you chose castration to avoid death you could commute your sentence by payment of a fine but as Sima Qian's family were poor he chose castration.
Regards
Michael Kerr