Answer: Mesopotamia, centered in modern-day Iraq, is regarded as the birthplace of civilization. While the region was widely occupied by humans as early as 12,000 B.C.E., historians believe that large civilizations began in Mesopotamia between 4,000 and 3,000 B.C.E. Mesopotamia's development in this period was supported by a series of geographical factors, including rivers and fertile lands. Hope this helps