Eliza is a main character from Neal Stephenson's The Baroque Cycle (consisting of the novels Quicksilver, The Confusion and The System of the World). Her last name is not revealed in a mysterious manner that suggests it may have some significance.

Eliza is a native of Qwghlm who as a young girl is abducted into slavery by Barbary pirates. Years later she is sold off to the Grand Turk to be a part of his harem. She is kept in a virginal state, so that the Grand Turk might have a virgin slave girl with whom to celebrate the fall of Vienna. When the Turkish armies fail to take Vienna, the harem virgins are ordered put to death, but at the last moment Eliza is rescued by Jack Shaftoe, with whom she has many adventures across Europe.

Eliza's shrewdness and financial acumen combine with her sexual attractiveness to earn her entry into the highest ranks of European society. She is made an unwilling spy for Louis XIV, who makes her a Countess, and a much more willing spy for William of Orange, who promises to make her a Duchess. Meanwhile she connives with Gottfried Leibniz to undermine the French war against the German states, and with Bob Shaftoe , the brother of Jack.

All the while, Eliza seeks to find the identity of the man who is responsible for her enslavement. This, the reader learns early on, is the Duc d'Arcachon . Eliza discovers this much later, only after she has become embedded in the d'Arcachon household.

Eliza (along with Louis XIV's cryptographer Bonaventure Rossignol ) is an ancestor of Rudolph von Hacklheber from Stephenson's earlier work, Cryptonomicon.