under Almoravid control. Notwithstanding, perhaps the weakest aspect of Almoravid rule in Spain and the Maghreb is the fact that they were a Muslim Berber minority in charge of a Spanish-Arab empire. With the passage of time, they found it increasingly difficult to protect all their territorial possessions from the Christian reconquest, especially in the aftermath of the fall of Saragossa in 1118. Moreover, in 1125 the Almohads (those who advocated the "Unity of Allah"), a confederation of rival Berber tribes, began to rebel against them in the Atlas Mountains. Following a protracted struggle and relentless fighting, the Almohads defeated the Almoravids in 1147; they transformed Marrakesh into their own capital and extended their authority into Muslim Spain. The position of the Jews under Almoravid domination was apparently free of major abuses, though there are reports of increasing social hostility against them – particularly in Fes. Unlike the problems encountered by the Jews during the rule of the Almohads (the Almoravids' successor dynasty), there are not many factual complaints of excesses, coercion, or malice on the part of the authorities toward the Jewish communities. It is known, however, that Yusuf Ibn Tashfin forbade Jews living in the capital city Marrakesh. It was allowed for them to trade there, but if a Jew was caught in the city during night hours it was punishable by death. Under the Almoravids, some Jews prospered (although far more so under Ali III, than under his father Yusuf ibn Tashfin). Among those who held the title of "vizier" () or "nasih" () in Almoravid times were the poet and physician Abu Ayyub Solomon ibn al-Mu'allam, Abraham ibn Meïr ibn Kamnial, Abu Isaac ibn Muhajar, and Solomon ibn Farusal. Under the Almohads (1146–15th century) The Dhimmi status, which called for the payment of jizya (taxes for non-Muslims) in exchange for a certain level of protection for religious minorities, came to an end under the strict militant dynasty of the Almohads, who came into power in 1146. Instead, the Almohads forced Jews to choose between conversion to Islam or death, compelling many Jews to convert, or at least pretend to. Due to the many similarities between Jewish and Islamic practice, Jews felt as though they could clandestinely maintain their Jewish practices under the guise of Islam. Maimonides, who was staying in Fez with his father, is said to have written to the communities to comfort and encourage