He had designated his son Muhammad al-Sheikh al-Ma'mun as his heir as early as 1579 and again in 1584, but he had also given all of his sons administrative roles during his reign. Upon his death in 1603, Al-Ma'mun's accession was immediately contested by his two brothers, Abu al-Ma'ali Zaydan al-Nasir (also known as Moulay Zaydan) and Abdallah al-Wathiq (also known as Abu Faris). Over the next 25 years the Saadian realm was split between a region ruled from Marrakesh and a region ruled from Fes, with the Sous sometimes also ruled separately, all of which changed hands between factions multiple times. Saadian authority outside these main centers of power was greatly diminished, and the trans-Saharan caravans from the south were sent to Marrakesh less frequently. Abu Faris initially held Marrakesh until 1606 while Moulay Zaydan held Fes for a year before being defeated and expelled by Al-Ma'mun in 1604, who then ruled from Fes. In the period around 1606 Marrakesh changed hands especially frequently – as many as six times according to one source – but Abdallah al-Ghalib II, a son of Al-Ma'mun who now also claimed the throne, managed to hold it between 1606 and 1609. Al-Ma'mun himself, meanwhile, saw his position in Fes weaken and sought help from abroad. At first he solicited help from Tuscany but in the end he was forced to flee and seek refuge in Spain in March 1608. Moulay Zaydan, who had fled to the Sous after being expelled from Fes, retook Marrakesh in 1609 with the help of Ottoman, English, and Dutch weapons. Around the same time (in 1609), Abdallah al-Ghalib II had Abu Faris assassinated and took control of his father's former realm in Fes, which he ruled until 1623. Al-Ma'mun attempted to make a comeback by agreeing to cede the northern port city of Larache to Spain in return for Spanish military assistance. In November 1610 he landed in Larache with Spanish troops under the command of Marquis of San Germán and tried to intimidate the elites of Fes into recognizing him as ruler. However the plan backfired as his surrender of Moroccan territory to the Spanish instead cost himself and the wider Saadian dynasty a great deal of credibility. He was eventually assassinated in 1613. This left his son, Abdallah al-Ghalib II, as ruler of Fes and his brother, Moulay Zaydan, as ruler of Marrakesh. Moulay Zaydan spent