British adventurer and author, Walter Harris, called Ouezzane of the late 19th century "the most fanatical that Europeans may visit". Positioned right on the border to the lawless territory known as Bled es-Siba and with one of the major religious cults of Morocco, Ouezzane's shaykhs had full freedom to define their own ways.
Some of the fanaticism may stem from the town's historical background being founded by refugees driven out of Andalucia after the Christian takeover.
Ouezzane developed into a popular religious centre in the 18th century when a zawiyya was established by the Sufi leader, Moulay Abdullah Sharif. Local Jews built a sanctuary around Rabbi Amrane ben Diwane, 9 km north of town, at Azjem. Both sites have festivals that have survived into modern times.