Ludwig Zamenhof, of House Karr-tir, was a specialist in Gemcutting, who worked with M and the Dead King. He was married to Henrietta Zamenhof, and they had a son, Albert Henry Zamenhof. Their son died of cyan tuberculosis.

Zamenhof was very interested in the occult and the magical. He bought one of the city's many criers, but was unable to make it work and it folded, losing the family a substantial fortune. He was an avid reader of Bedlam Thorn's column.

When he died, he put a geas on Liang Qi, forcing him to return his son's bones to his grave.