The trade of the Red Sea with India had up to this period been a very considerable one, but owing to the misgovernment of the Imams, and their inability to offer security to traders, it had greatly diminished in the last few years. On this account Sir Home Popham was sent on a special mission to the Yemen in 1801, and was nominated Ambassador to the Southern Arabian states. He arrived at Mokha on his return from Calcutta in 1802, and set out for Sanaa. However, he reached only as far as Taiz, and there, as had been the case along the entire route, he was treated with every ignominy. The Imam protested that the treatment of the Ambassador had been carried on without his knowledge and contrary to his orders, and he promised to punish the offenders. In all probability Ali Mansur, who then held the throne at Sanaa, was entirely unable to cope with the turbulent tribes, and it is known for certain that from his extravagances he was always in arrears with the subsidised chiefs of the neighbouring districts. I have briefly mentioned elsewhere the Wahabi sect, which, under the leadership of Abd el-Wahab en-Nejdi, sprang up in the eighteenth century. It had not, however, seriously made itself felt in the Yemen until this period, its progress being no doubt largely influenced by the Wahabi conquest of Mecca and Medina. During the years 1804 and 1805 the Yemen suffered from continual raids of the Wahabi leaders, for the most part chiefs of the Beni Asir, the tribes lying between the Hejaz and the Yemen proper. But treachery was on foot, and certain Shereefs nominally owing allegiance to the Wahabi doctrine were really working in the interests of the Imam of Sanaa, and in this manner the marauders were held more or less in check. Meanwhile the Imam Ali Mansur had been deposed by his son Ahmed, who had seized the reins of government. But the city of Mokha refused to acknowledge Ahmed while the old Imam was still alive, and on that account Ahmed put an expedition into the field against the Dowla of that town. Happily for the country Ali Mansur died, and the people of Mokha were then able to acknowledge his son as Imam, and so a disastrous war was staved off. So great had become the power of the Wahabis that in 1813 Mahammed Ali Pasha invaded the Hejaz in the name of Turkey, and restored Mecca and Medina to the Osmanli Sultan. Thence an envoy was sent to the Imam at Sanaa, requesting his co-operation in the stamping out of the Wahabis. This was readily granted, for the Imam evidently saw that Mahammed Ali’s eyes were turned in the direction of the Yemen; and although he protested that he himself was devoid of means to carry on warfare, he gave the envoy letters to the Dowla of Mokha to supply him with vessels and material, knowing full well that he possessed neither.[23]