Turki bin Abdullah bin Muhammad and his successors rule from Riyadh over a wide area.

They control the region to the north and south of Najd and exert considerable influence along the western coast of the Persian Gulf.

This area is no state but a large sphere of influence that the Al Saud hold together with a combination of treaties and delegated authority.

In the Jabal Shammar to the north, for instance, the Al Saud support the rule of Abd Allah ibn Rashid, with whom Turki maintains a close alliance.

Later, Turki's son will Faisal cement this alliance by marrying his son, Talal, to Abd Allah's daughter, Nura.

Although this family-to-family connection works well, the Al Saud prefer to rely in the east on appointed leaders to rule on their behalf.

In other areas, they are content to establish treaties under the terms of which tribes agree to defend the family's interests or to refrain from attacking the Al Saud when the opportunity arises.