Arabic History

Bahrain

• Encyclopaedia of the Orient — Brief history of Bahrain, including politics, economics, health, and more.
• History of the National Flag — Complete with dates and pictures.

Jordan

• Jordan: Key to the Kingdom — A well-designed and comprehensive website about the history of Jordan.

Kuwait

• The Rich History of Kuwait — Beautiful site with an overview of the rich history of Kuwait.
• Arab.net's History of Kuwait

Saudi Arabia

• Saudi Arabian Information Resource — Large site dedicated to proliferating information about Saudi Arabia. I'm sure you can find some history in there somewhere.
• A Country Study: Saudi Arabia — Prepared by the Library of Congress.

Yemen

• Queen of Sheba (oh, so she was Yemenese?)
• Women in Ancient Yemen
• Plain Tales from the Sands