The first Saudi regime (1745-1818, founded by Imam Muhammad bin Saud) was characterised by an uncontested lineal succession and overall stability. Potential challengers from the lineal line (Muhammad's other sons) were either too young to pose a threat or had been killed in battle. Claimants from the lateral lines (brothers of the first Imam - Thunayyan, Mishari and Farhan) were not yet prominent. Muhammad's son Abd al-Aziz was designated heir apparent (wali al-ahd) and military chief, establishing a pattern which formed the template for later succession. When Abd al-Aziz, after greatly expanding the Saudi realm, in turn designated his son Saud as heir apparent in 1788, his choice was uncontested. Saud's military prowess secured his claim, and after Abd al-Aziz was assassinated in Karbala, he was proclaimed Imam without opposition. Neither his uncles or brothers challenged his rights.
Saud in turn appointed his son Abdallah as successor, but when Saud unexpectedly died in 1814, the succession was contested by an uncle, Abdallah bin Abd al-Aziz (Saud's full brother). The uncertain military performance of the Saudi forces against an invading Egyptian army sent
by the Ottomans had raised doubts about the leadership ability of the wali al-ahd. Although nothing came of Abdallah's bid, it does represent the first instance of a succession challenge taking place at a time of external danger to the realm.
The Egyptian invasion put an end to the first Saudi realm, and the ruling family would have been eliminated entirely had not a few members (notably Turki bin Abdallah) managed to escape and take shelter with the bedouin. Turki reappeared in 1823 and was able to establish a new capital at Riyadh. The dynasty had been shattered, however, and there was no longer a clear line of succession. As a result, the second Saudi state was characterised by a greater number of succession disputes as different family branches vied to claim their inheritance rights. Competing claims made it more difficult for a ruling Iman to retain control, while at the same time the constraints imposed by the realisation that further expansion of the realm would provoke another devasting response from outside limited the opportunities for potential claimants to demonstrate their military prowess and distinguish themselves over their rivals.
In the end, Turki established his dominance, but only after a series of family struggles. Like his predecessors, he tried to pass the succession on to his eldest son, Faysal, who had escaped from prison in Egypt in 1827, but reestablishing a pattern of lineal succession proved impossible in the face of rivalries among the sons of Faysal. Though Turki embarked on a series of successful campaigns, his own claim was subject to challenge by collateral branches, and he was assasinated in 1834 by a cousin from the Mishari branch. A period of strife and rapid leadership changes followed, until Turki's son Faysal, having once again escaped from Egyptian captivity in 1843 (the Nejd had been invaded in support of another challenger, Khalid bin Saud, from the original ruling branch), retook Riyadh, which was by this time held by yet another pretender, Abdallah bin Thunayyan.
Faysal consolidated the second Saudi state, ushering in a period of stabililty grounded in Faysal's personal prestige, and buttressed by personal ties and loyalties. Sons and daughters were married to rivals, supporters were handed important governorates, and a series of political alliances with notable families such as the al-Sudayri date from this time. With Faysal now the dominant figure in family politics, another attempt at lineal succession was made. Tensions among his four sons ran high, however. Abdallah and Muhammad were full brothers, as were Saud and Abd al-Rahman, from a woman of the Ajman tribe. In typical fashion, Faysal appointed his eldest, Abdallah, as heir apparent and military chief.