T h e first difficulties that traders from Madagascar met with seem to have been related to the ineffectiveness of the alliance between
Axum and Byzantium against Sassanid Persia. Th e Sassanids, thanks to the conquest of South Arabia (570) which they remained in control of until the conversion of the last governor to Islam in 628,** succeeded no doubt in partially taking over the legacy of the South Arabians in the sea trade in the Indian Ocean, including the Red Sea. The n conquered - and soon converted - Persia was to some extent integrated to the expansionist policy of the Arab-Islamic world, whose conquest of
Egypt (641-2) completed the seizure of control of the trade routes in the west by the Arabs and Persians.
Whether active or passive, the initial adaptation of the Island to this situation manifestly consisted in entering into relations with Persian speaking importers, which is what explains ho w their influence is perceptible through the data yielded by the soil of Madagascar. Som e of them were, moreover, probably present on the African coast. But the at least partial change in partners and the interruption of overland routes, which lay behind not only the decline in the incense trade but also no doubt that in other products coming up against competition with those of the Arab-Persian world, also perhaps impeded the trade in cinnamon, which was already in competition with Ceylon which had been backed by the Sassanids since the fourth century. And when, taking advantage of the troubles at the end of the seventh and beginning of the eighth century in South Arabia, it seems,69 the people of al-Kumr (Comoros and Madagascar) embarked on the conquest of Aden in their outrigger boats, it should perhaps be seen as a partially successful attempt to restore the situation. For these conquerers, some of who m had settled dow n in Yemen , and had mad e Aden into their home port from where they would set out each season, 'sail[ing] together in a single monsoon', had succeeded in establishing a direct sailing route between their country of origin and south Arabia, a voyage that the Arabs and Persians in the thirteenth century, according to the testimony of Ibn al-Mudjäwir, were still taking three monsoons to complete. Thus, in spite of everything, they were able to compete with their rivals, since the Arab and Persian seafarers, wh o seem not to have known of the Comoros and Madagascar until the tenth century — and only had a clear idea of them by the twelfth century - continued to receive Malagasy products on the East African coast, which they would coast along.
