An inscription, found in Palmyra and dated to August 271, called Zenobia "eusebes" (the pious); this title, used by Roman empresses, could be seen as a step by the queen toward an imperial title. Another contemporary inscription called her "sebaste", the Greek equivalent of "empress" (Latin: "Augusta"), but also acknowledged the Roman emperor. A late-271 Egyptian grain receipt equated Aurelian and Vaballathus, jointly calling them "Augusti". Finally, Palmyra officially broke with Rome; the Alexandrian and Antiochian mints removed Aurelian's portrait from the coins in April 272, issuing new tetradrachms in the names of Vaballathus and Zenobia (who were called "Augustus" and "Augusta", respectively).