Final answer:
The Great Mosque in Damascus, also known as the Uma.yyad Mosque, was completed in 715 CE, having been started in 706 CE during the reign of Caliph al-Walid I.
Step-by-step explanation:
The Great Mosque in Damascus, also known as the Uma.yyad Mosque, was completed in 715 CE. Built under the Uma.yyad dynasty, the mosque was designed to accommodate the growing number of followers of Islam and served as a major site for congregational worship. The construction began in 706 CE under the rule of Caliph al-Walid I and was completed nine years later, becoming one of the earliest surviving congregational mosques and an architectural landmark. The mosque not only signified the religious fervor of the time but was also a symbol of the political power of the Uma.yyads, constructed from a prodigious sum of state tax revenues and intricately decorated with mosaics and marble.