From Chinese 尹 (yǐn), a title for a ministerial position in ancient China. It may also refer to the ancient fief of Yin, which existed in what is now either Shanxi or Henan province.
From Chinese 殷 (yīn) referring to the ancient city of Yin, which existed in what is now Henan province and served as the capital of the Shang dynasty (which reigned from 1600 to 1045 BC and was also called Yin).