This volume presents part of the author's research on the Achaemenid Royal Inscriptions recovered in the ruins of the Achaemenid palaces in Susa, conducted within the framework of the DARIOSH-Louvre Project. It offers a new study of several fragmentary inscriptions in Old Persian, Achaemenid Elamite, and Achaemenid Babylonian, currently designated as DSe, DSt, DSb, DSl, DSa, DSk, DSi, DSp, D (2)Sb, DSj, A (2)Se, DSs, 'Inc. Sb', and others. The book provides a new edition of each inscription based on both published and unpublished fragments. Additionally, it introduces some new lexicons and cuneiform signs in the Old Persian language and script.