In 1744, the religious reformer Muhammad ibn Abd al-Wahhab was expelled from ʿUyaynah and moved to Diriyah. There he found protection under the local ruler, Muhammad ibn Saud. This relocation set up a lasting link between religious preaching and political authority in central Arabia.
In 1744, Muhammad ibn Saud and Muhammad ibn Abd al-Wahhab formed an alliance often called the Diriyah Pact. The agreement tied the ruler’s military protection and state-building to the cleric’s religious reform program. This partnership became the core model for later Saudi states, with political leadership and Wahhabi religious authority reinforcing each other.
From 1746 to 1773, forces based in Diriyah fought a prolonged campaign to bring Riyadh under their control. Winning Riyadh expanded the First Saudi State’s influence in Najd and strengthened the alliance’s political reach. It also showed how the movement could turn local religious support into territorial expansion.
By the late 1700s, the Diriyah-based state had grown beyond a single town into a regional power. Leaders used military campaigns and alliances to spread Wahhabi teachings, while religious scholars provided legitimacy for rulers’ expansion. This created a feedback loop: territorial gains helped the religious movement spread, and the movement helped justify further gains.
On 21 April 1802, forces linked to the Emirate of Diriyah attacked Karbala in Ottoman Iraq, killing many residents and looting the shrine area. The raid deepened regional conflict, especially with Shiʿa communities, and heightened Ottoman concerns about security and religious authority. It became one of the most cited episodes used to justify a stronger Ottoman response.
In 1811, the Ottoman Empire tasked Muhammad Ali Pasha of Egypt with defeating the Diriyah-based Saudi-Wahhabi state. The resulting Ottoman–Wahhabi war aimed to reassert Ottoman control and protect pilgrimage routes and holy cities. This marked a major turning point: external imperial power directly challenged the state created by the Saudi–Wahhabi partnership.
From 22 April to 9 September 1818, Ibrahim Pasha’s forces besieged Diriyah and ultimately forced its surrender. The defeat dismantled the First Saudi State’s political structure and disrupted the clerical-ruling alliance’s ability to govern territory. Even so, the religious ideas and family networks behind the movement survived and later re-formed around new centers.
In 1824, Turki bin Abdullah re-established Saudi political authority by taking Riyadh and making it the capital. This began the Second Saudi State (Emirate of Najd), showing that the Saudi project could recover after military defeat. Religious legitimacy continued to matter, but the state now had to rebuild amid rival powers and lingering Ottoman influence.
On 21 January 1891, the Battle of Mulayda ended in a decisive victory for the Emirate of Jabal Shammar (the Rashidis). The defeat forced the House of Saud into exile and ended the Second Saudi State. This collapse created the conditions for a later return, when a new generation would rebuild power while again drawing on religious alliances.
On 15 January 1902, Abdulaziz Ibn Saud seized Riyadh in a surprise attack that became the starting point for rebuilding Saudi power. The capture restored a territorial base for the Al Saud after years of exile. From this base, he expanded through alliances, warfare, and renewed religious backing that helped unite followers behind his rule.
In April 1913, Ibn Saud’s forces took al-Hasa from an Ottoman garrison, bringing an important eastern oasis region under his control. The conquest strengthened the emerging Saudi state economically and strategically by widening its territory and access to the Gulf. It also showed how religiously motivated fighters could be integrated into state expansion.
On 26 December 1915, Ibn Saud signed the Treaty of Darin with the United Kingdom. The agreement shaped relations and boundaries during World War I-era politics in the Gulf, while also reflecting British interest in stability near their protectorates. It gave Ibn Saud more room to consolidate power as the Ottoman position weakened.
From 10 February to 17 December 1925, Saudi forces besieged Jeddah, the last major Hashemite stronghold in Hejaz. The city’s surrender removed the main barrier to Ibn Saud’s control over the Red Sea coast and the region that includes Mecca and Medina. This victory expanded Saudi authority over sites central to Islamic life and increased the political importance of religious legitimacy.
In early January 1926, Ibn Saud was proclaimed King of Hejaz after the collapse of Hashemite rule. The proclamation formalized his control over the western region and the holy cities, linking political sovereignty to religious authority in a new way. It also set the stage for a larger, unified kingdom built from multiple regions and loyalties.
On 20 May 1927, the United Kingdom signed the Treaty of Jeddah with Ibn Saud. The treaty recognized the independence and sovereignty of Ibn Saud’s realm (the Kingdom of Hejaz and Nejd) and required limits on cross-border raids into neighboring British protectorates. Diplomatic recognition strengthened the state’s position as it moved from conquest toward administration and governance.
From 29 to 31 March 1929, Ibn Saud’s forces defeated rebellious Ikhwan fighters at the Battle of Sabilla. The Ikhwan had been a key religious-military force in expansion, but the revolt showed tensions between strict religious militancy and the needs of a modernizing state (including new technology and diplomacy). The defeat helped centralize authority under the ruler and reduced the independent power of militant religious fighters.
On 23 September 1932, a royal decree renamed the Kingdom of Hejaz and Nejd (and its annexes) as the Kingdom of Saudi Arabia. The proclamation marked the end point of a long cycle of alliance-building, collapse, restoration, and expansion that began with the Diriyah partnership. It also set a new framework in which religious authority remained important, but within a centralized kingdom recognized in international relations.
Wahhabi clergy and the religious foundation of the Saudi state (1744–1932)