During Sabaean rule, the area of modern-day Yemen was called "Arabia Felix" by the Romans who were impressed by its prosperity. Gallus undertook the expedition from Roman Egypt by the command of Augustus, in order to conclude treaties of friendship with the Arabian people or to subdue them if they should oppose the Romans. Indeed, it was believed at the time that Arabia was full of all kinds of treasures: the success of the Kingdom of Saba was based on the cultivation and trade of spices and aromatics including frankincense and myrrh.