By the Sword is a pivotal book in Lackey's major body of fantasy fiction, the Valdemar books. By Tarma and Kethry's presence it connects the Vows and Honor duology with the many novels set in Valdemar proper. In the series' time line, By the Sword takes place during and soon after the Arrows trilogy and before the Mage Winds trilogy. Kerowyn, who stays in Valdemar and becomes arms instructor to Elspeth, the heir to Valdemar's throne, appears in the latter trilogy, but as a secondary character. The Gryphon, Herald-Mage, and Storms trilogies are also set in this world during other eras.