as ambassador to Elizabeth's court to negotiate a military alliance to invade Spain. In his letter to the Queen he even suggested a second option to invade Spanish colonies in the New World and expressed a desire for Morocco to colonize those territories if they were victorious. Elizabeth did not agree to either plan, but commercial relations continued to develop. Conquest of the western Sudan under Al-Mansur Al-Mansur's only major foreign military venture was the invasion of West Africa – or more particularly the western Sudan, as it was known in Arabic. This was likely motivated by a number of factors. Trans-Saharan trade had long been an important part of Morocco's place in international trade and the tax revenues from it had contributed to funding the Saadians ever since their early days in the Sous. The expansion of European trade routes around the whole coast of Africa, however, had undermined its importance and reduced the flow of gold across the desert. Thus Al-Mansur may have sought to increase his access to gold through direct control of the gold mines in the south. Saadian interest in the sugar trade may have also been a motivation, as control of the trans-Saharan trade routes also allowed him to increase Morocco's access to slaves – on which the sugar processing industry relied and which were necessary to compete with the prices of sugar coming from Brazil and the Caribbean (controlled by Europeans and also reliant on slaves). Finally, the invasion may have been a way for Al-Mansur to elevate his claim to being a universal Muslim ruler. Since expansion eastward into Ottoman territory had been unfruitful the only path left for Saadian expansion was to the south. This ambition may have been further encouraged by the embassies of Idris Alooma, the Mai (king) of the Kanem-Bornu Empire, who, having failed to secure support from the Ottoman Empire, expressed willingness to recognize Al-Mansur as caliph instead. Saadian interest in the Sudan region preceded Al-Mansur. Earlier that century the Saadians occupied the oasis area of Touat for a time and Ahmad al-'Araj had asked Askia Ishaq I (r. 1539–1549), emperor of the Songhai Empire, to grant him control of the Taghaza salt mines. Since Al-Araj and his successors were preoccupied with challenges to the north, this claim was not pursued further. In 1583 or 1584, however, Al-Mansur brought the issue up again with Emperor Askia Dawud