The Caylus vase is a jar in alabaster dedicated in the name of the Achaemenid king Xerxes I in Egyptian hieroglyph and Old Persian cuneiform. It was the key element in confirming the decipherment of Old Persian cuneiform by Grotefend, through the reading of the hieroglyphic part by Champollion in 1823. It also confirmed the antiquity of phonetical hieroglyphs before the time of Alexander the Great, thus corroborating the phonetical decipherment of the names of ancient Egyptian pharaohs. The vase was named after Anne Claude de Tubières, count of Caylus, an early French collector, who had acquired the vase in the 18th century, between 1752 and 1765. It is now located in the Cabinet des Médailles, Paris (inv. 65.4695).