The Planetary Grand Duchy of Sphinx was one of the highest-ranking peerages in the Star Kingdom of Manticore, encompassing the planet Sphinx.[1]

In the early 20th Century PD, the Grand Duchess of Sphinx was one of the few nobles to still outrank Honor Harrington after she had become Steadholder Harrington. (HH6)


  1. According to Harrington, only 3 Manticoran peerages outranked her; the Grand Duchy of Manticore, Grand Duchy of Gryphon, and Grand Duchy of Sphinx.