The Elements Effective on Reducing the Economic Efficiency of Iraq’s River Shipping Activities in Abbasid Era (132-334 A.H)

Abbasids paid attention to the development of river shipping during their Caliphate. They made lots of military, commercial uses from both Tigris, Euphrates rivers. The existence of internal barriers negatively affected the shipping activities in these two rivers, which is the main question that this research is based on. The research is to find the answer to question on what factors caused the reduction of shipping activities in Tigris and Euphrates rivers in Abbasid era (132 - 334 A.H). The research findings indicate that the human factors such as the internal riots as well as the internal and external thefts, the increase of customs duties and the natural factors such as the winds, floods, muds of rivers are considered the elements effective on lessening the economic efficiency of shipping activities.