In 693, the Byzantine gold "solidus" was replaced in Syria and Egypt with the dinar. Initially, the new coinage contained depictions of the Caliph as the spiritual leader of the Muslim community and its supreme military commander. This image proved no less acceptable to Muslim officialdom and was replaced in 696 or 697 with image-less coinage inscribed with Qur'anic quotes and other Muslim religious formulas. In 698/99, similar changes were made to the silver dirhams issued by the Muslims in the former Sasanian Persian lands of the eastern Caliphate. Arabic replaced Persian as the language of the "dīwān" in Iraq in 697, Greek in the Syrian "dīwān" in 700, and Greek and Coptic in the Egyptian "dīwān" in 705/06. Arabic ultimately became the sole official language of the Umayyad state, but the transition in faraway provinces, such as Khurasan, did not occur until the 740s. Although the official language was changed, Greek and Persian-speaking bureaucrats who were versed in Arabic kept their posts. According to Gibb, the decrees were the "first step towards the reorganization and unification of the diverse tax-systems in the provinces, and also a step towards a more definitely Muslim administration". Indeed, it formed an important part of the Islamization measures that lent the Umayyad Caliphate "a more ideological and programmatic coloring it had previously lacked", according to Blankinship.