Fortunately for Muhammad, the more “enlightened” citizens of Medina extended an invitation to the Muslims to come and live in their city. It is not recorded whether or not they held up large “welcome refugees” banners as is now the custom at European train stations, but they soon enough experienced the kind of regrets that Europeans are now having.
Muhammad gradually acquired wealth and converts, and within a half-dozen years he was the master of Medina. Those Medinans who were not exiled or slaughtered were thoroughly subjugated. Muhammad then used Medina as the launching pad for his conquest of all Arabia.
Within a century of his death, his followers had conquered nearly half of the civilized world.
- William Kilpatrick in Crisis Magazine