The Persian Gulf during the 7th century till the early 10th century witnessed huge economic and cultural relations between communities around the sea in the south and north. This research describes the historical geography of the coasts of the Persian Gulf and the gulf of Oman during those centuries to answer the question: "What was the geographical context of the economic flourishing of the Persian gulf coasts in this period?" Available evidence supports the hypothesis that "the proximity of the northern and southern shores of this sea to each other, remoteness of coasts and ports of major empires and finally climate change for extensive farming, were the important geographical factors for cultural and economic relations of people in this region and consequently the prosperity of economic activities." This research was done in historical method and data collection was done by library techniques. The data from the seventh and tenth centuries primary sources was collected and then analyzed.