سقوط زرنگ؛ ظهور شهر سیستان

Many researchers, historians, geographers, and sistanologists believed that the city of zarang was the same city of sistan. this city since its establishment in the late sasanian period up to the year 785 ah that amir timur attacked and destroyed it and in the year 811 ah by the attack of timurid shahrukh it was completely destroyed, was the capital of sistan. the writer of these lines believes that city of sistan had been a completely different city, independent of the city of zarang, and in the second half of the fourth century ah, that the city of zarang lost its centrality and political credibility, it had been replaced by city of sistan and it had been the capital of sistan province till the first half of the ninth century ah.the purpose of this research is based on fundamental research and on the nature and methods of historical research. the author has tried to study the change of capital from zarang to city of sistan based on the historical sources and by reflection on their writing. in other words, the author has tried to study the fact that zarang is not the same as city of sistan as a historical fact and has tried to prove its accuracy by providing clear and concrete evidence.