As the Arabian cities prospered, the old tribal governments were no longer sufficient. Arabia was ruled by hundreds of sheiks, instead of one central government. They all shared the same language, culture and religious beliefs, but because they did not share the same government and were not united, it was difficult for them to defend themselves.
The Persian Empire and the Byzantine Empire were both growing in strength and influence. Both of these Empires looked at Arab lands and threatened to conquer them.
If you can play golf and bridge as though they were games, you''re just about as well adjusted as you are ever going to be.
The custom of shaking hands with strangers originated to show that both the parties were unarmed.