The world had paid the Al Saud scant attention while they remained in Najd, but their capture of the Hijaz  brings their empire into conflict with the rest of the Islamic world.

The popular and Shia practices to which the Wahhabis object are important to other Muslims, the majority of whom are alarmed that shrines are destroyed and access to the holy cities restricted.

Moreover, rule over the Hijaz is an important symbol.

The Ottoman Turks, the most important political force in the Islamic world at the time, refuse to concede rule over the Hijaz to local leaders.

The Ottomans at the beginning of the nineteenth century are not in a position to recover the Hijaz, because their forces are weak and overextended.

Accordingly, the Ottomans delegate the recapture of the Hijaz to their most ambitious client, Muhammad Ali, the semi-independent commander of their garrison in Egypt.

Muhammad Ali, in turn, hands the job to his son Tusun, who leads a force to the Hijaz in 1816; Muhammad Ali later joins his son to command the force in person.

Muhammad ibn Abd al Wahhab had meanwhile, died in 1792, and Abd al Aziz died shortly before the capture of Mecca.

The movement had continued, however, to recognize the leadership of the Al Saud and so followed Abd al Aziz's son, Saud, until 1814; after Saud died in 1814, his son, Abd Allah, ruled.

Accordingly, it is Abdullah bin Saud bin Abdul-Aziz who faces the invading Egyptian army.

Tusun's forces take Mecca and Medina almost immediately.

Abdullah chooses this time to retreat to the family's strongholds in Najd.

Ottoman sultan Mahmud III, appalled at the At-Ta'if slaughter and the Saudi capture of the holy cities but preoccupied in other directions, assigns the task of crushing the Wahhabi “heretics” to Muhammad (Mehmet) 'Ali Pasha, the virtually independent viceroy of Egypt.

Acknowledging the sovereignty of the Ottoman Sultan and at his command, Muhammad Ali dispatches an army of twenty thousand men (including two thousand horses) under the command of his son Tusun, a youth of seventeen; the Egyptians land on the Hejaz coast.

By the end of 1811, Tusun has received reinforcements and captured Medina after a prolonged siege.

The Wahhabi movement, a fundamentalist sect within Islam founded by Muhammad ibn Abd-al-Wahhab, will lead to creation of the Emirate of Diriyah as he and Muhammad bin Saud launch their campaign to reform Islam and consolidate power in Arabia from their power-base, and its eventual crushing by the Khedive, Muhammad Ali of Egypt, the semiautonomous  viceroy of the Ottoman Empoire.

The Wahhabi sack of Karbala in 1802 had resulted in five thousand deaths and the plundering of the Imam Husayn Shrine; by 1805, the Wahhabis controlled Mecca and Medina.

The Wahhabis also attack Ottoman trade caravans, which interrupts the Ottoman finances.

The Saudi amir has denounced the Ottoman sultan and called into question the validity of his claim to be caliph and guardian of the sanctuaries of the Hejaz.

The Ottoman Empire, suspicious of the ambitious Muhammad Ali, have instructed him to fight the Wahhabis, as the defeat of either would be beneficial to them.

Tensions between Muhammad Ali and his Albanian troops also prompt him to send them to Arabia and fight against the Wahhabi movement, where many die.

Muhammad Ali had been ordered as early as December 1807 by Sultan Mustafa IV to crush the Saudi state, but internal strife within Egypt had prevented him from giving full attention to the Wahhabis.

The Albanians are not able to recapture the holy cities until 1811.

The Mamluks still pose the greatest threat to Muhammad Ali.

They had controlled Egypt for more than six hundred years, and over that time they had extended their rule systematically south along the Nile River to Upper Egypt.

Muhammad Ali’s approach is to eliminate the Mamluk leadership, then move against the rank and file.

Muhammad Ali invites the Mamluk leaders to a celebration at the Cairo Citadel in honor of his son, Tusun Pasha, who is to lead a military expedition into Arabia against the Saudi-Wahhabis.

The event is held on March 1, 1811.

When the Mamluks have gathered at the Citadel, and are surrounded by Muhammad Ali's troops, he has his troops kill them.

After the leaders are killed, Muhammad Ali dispatches his army throughout Egypt to rout the remainder of the Mamluk forces.

Egyptian reinforcements enable Tusun Pasha to occupy Mecca and ...

...Medina in 1812.

Muhammad 'Ali assumes personal command of the expeditionary force in the Hejaz in 1813.

The modern history of Arabia is often broken into three periods that follow the fortunes of the Al Saud.

The first begins with the alliance between Muhammad ibn Saud and Muhammad ibn Abd al Wahhab and ends with the capture of Abd Allah.

The second period extends from this point to the rise of the second Abd al Aziz ibn Saud, the founder of the modern state; the third consists of the establishment and present history of the Kingdom of Saudi Arabia.

In the Egyptians' attempt to establish control over the peninsula, Muhammad Ali removes members of the Al Saud from the area.

Following orders from the Ottoman sultan, he sends Abdullah to Istanbul—where he is publicly beheaded—and forces other members of the family to leave the country.

A few prominent members of the Al Saud find their way to Egypt.

The Egyptians turn next to the symbol of the Al Saud rule, the city of Ad Diriyah.

They raze its walls and buildings and destroy its palm groves so that the area cannot support any agricultural settlement for some time.

The Egyptians now send troops to strategic parts of the peninsula to tighten their grip on it.

They garrison Al Qatif, a port on the Persian Gulf that supplies some of the important centers in eastern Arabia and maintain various forces along the Red Sea coast in the west.

Muhammad Ali of Egypt decides to pursue Abdullah to Najd, sending out another army under the command of his other son, Ibrahim.

The Wahhabis make their stand at the traditional Al Saud capital of Ad Diriyah, where they manage to hold out for two years against superior Egyptian forces and weaponry.

In the end, however, the Wahhabis prove no match for the Egyptian forces, and Ad Diriyah—and Abdullah with it—falls in 1818.