Battle of ad-Dir'iyah, (1818), major defeat dealt the Wahhabis, fanatical and puritanical Muslim reformers of Najd, central Arabia, by the forces of the Egyptian ruler Muhammad 'Ali Pasha; the Wahhabi empire was destroyed, and the Sa'udi family that created it was virtually wiped out.

Wahhabi attacks on pilgrim caravans crossing Arabia concerned the Ottoman Turkish government at the end of the 18th century (the Ottoman sultan was protector of Mecca, Islam's chief holy city). When the Ottomans attempted to invade al-Hasa', eastern Arabia, the Wahhabis responded by seizing the holy city of Karbala' in Turkish Iraq (1801), then capturing Mecca itself (1802). Preoccupied in other directions, the Sultan did not send another force into Arabia until 1811, when he consigned to Muhammad 'Ali Pasha, the virtually independent viceroy of Egypt, the task of crushing the "heretics." For the next four years, the balance of power shifted back and forth between Muhammad 'Ali and Sa'ud.

In 1815 Sa'ud's successor, 'Abd Allah I, sued for peace, and the Egyptians withdrew from Najd. The following year, however, Ibrahim Pasha, one of the Viceroy's sons, took command of the Egyptian forces. Gaining the support of the volatile Arabian tribes by skillful diplomacy and lavish gifts, he advanced into central Arabia to occupy the towns of 'Unayzah, Buraydah, and Shaqra'. Joined now by most of the principal tribes--Harb, 'Unayzah, Mutayr, Banu Khalid--he appeared before the Wahhabi capital ad-Dir'iyah in April 1818. After six months of intermittent and desperate fighting, 'Abd Allah surrendered (Sept. 9, 1818) and was sent to Constantinople, where he was beheaded. Ad-Dir'iyah was razed to the ground, and Egyptian garrisons were posted to the principal towns. Several members of the Sa'udi family managed to escape before the surrender; the rest were sent to Egypt to prison.