Representatives of Ibn Saud’s Najd and Britain (acting for Mandatory Iraq and Kuwait’s interests) agreed on boundary lines at Uqair. The protocol drew borders with Iraq and Kuwait and created two “neutral zones,” reflecting the difficulty of fixing borders in areas used by mobile tribes. This was a major step from frontier influence to mapped territorial claims.
The Uqair settlement left a strip of territory between Kuwait and Najd as a shared-use “neutral zone” (later called the Saudi–Kuwaiti Neutral Zone or Divided Zone). Both sides could exercise certain rights there, while a final partition was postponed. The arrangement shows how border-making often relied on special zones when exact ownership was disputed.
At the same time, the Uqair settlement created a second neutral zone along parts of the Iraq–Najd boundary. This was meant to reduce conflict over grazing routes and wells while giving time for later technical demarcation. Even though it was a “temporary” solution, it became a long-lasting border feature.
Tribal fighters associated with the Ikhwan movement rebelled against Ibn Saud’s authority and carried out raids toward Iraq, Kuwait, and Transjordan. These raids threatened relations with Britain and its protectorates and highlighted the gap between conquering territory and administering it. The revolt pushed Ibn Saud to centralize power and limit independent tribal warfare.
Britain and Ibn Saud signed the Treaty of Jeddah, recognizing the independence and sovereignty of Ibn Saud’s state (then the Kingdom of Hejaz and Nejd). In exchange, Ibn Saud agreed to restrain raids against neighboring British-protected territories, linking internal control to external border stability. The treaty strengthened the international status needed to negotiate and enforce borders.
At Sabilla, Ibn Saud’s forces decisively defeated the Ikhwan in one of the revolt’s main battles. The result reduced the ability of rebel groups to keep launching destabilizing raids across emerging borders. With internal challengers weakened, the state could more effectively enforce border discipline and pursue diplomatic settlements.
Asir, ruled by the Idrisi leadership, moved further under Saudi control when it was incorporated as a protectorate of the Kingdom of Hejaz and Nejd. This reduced Asir’s autonomy and placed its administration within Saudi structures. The step mattered for borders because Asir sat along the contested southwest frontier near Yemen.
In the early 1930s, elements of the Idrisi leadership attempted to reverse Saudi dominance in Asir, with regional rivalries feeding the unrest. The rebellion exposed how unfinished the southwest settlement remained and how local elites could appeal to outside support. Restoring control in Asir became closely tied to resolving the Saudi–Yemeni frontier.
A royal decree renamed the Kingdom of Hejaz and Nejd and its annexes as the Kingdom of Saudi Arabia, signaling a more unified national state. A clearer national framework made it easier to treat borders as state boundaries rather than personal or tribal spheres of influence. This proclamation also supported more consistent foreign relations and treaty-making.
Saudi Arabia and the Kingdom of Yemen fought a short war, driven by competing claims in the southwest (including areas tied to Asir, Jizan, and Najran). The conflict showed that border consolidation was not only about maps but also about control on the ground. The war ended when both sides accepted a negotiated settlement.
Saudi Arabia and Yemen signed the Treaty of Taif, ending hostilities and demarcating a major portion of their boundary. The settlement confirmed Saudi control of Asir while returning other areas to Yemen, creating a workable (though partial) border framework. It also established a long-term political basis for managing cross-border relations.
After the war and the Treaty of Taif, the Idrisi polity in Asir ceased to exist as an independent political entity, and Saudi authority was consolidated there. This outcome connected southwest state-building directly to an international settlement with Yemen. By 1934, Saudi Arabia had a clearer territorial shape and stronger tools to police its borders.
Border consolidation and regional settlements (1920–1934)