In October of 270, a Palmyrene army of 70,000 invaded Egypt, and declared Zenobia queen of Egypt. The Roman general Tenagino Probus was able to regain Alexandria in November, but was defeated and escaped to the fortress of Babylon, where he was besieged and killed by Zabdas, who continued his march south and secured Egypt. Afterward, in 271, Zabbai started the operations in Asia Minor, and was joined by Zabdas in the spring of that year. The Palmyrenes subdued Galatia, and occupied Ankara, marking the greatest extent of the Palmyrene expansion. However, the attempts to conquer Chalcedon were unsuccessful.