The emergence of the Saudi dynasty began in central Arabia in 1744. In that year, Muhammad ibn Saud, the tribal ruler of the town of Ad-Dir'iyyah near Riyadh, joined forces with the religious leader Muhammad ibn Abd-al-Wahhab, the founder of the Wahhabi movement. This alliance formed in the 18th century provided the ideological impetus to Saudi expansion and remains the basis of Saudi Arabian dynastic rule today. Over the next 150 years, the fortunes of the Saud family rose and fell several times as Saudi rulers contended with Egypt, the Ottoman Empire, and other Arabian families for control of the peninsula.