The Harappan civilisation did not exist in isolation. There were a few other important civilisations which existed at the same time period. These were the Mesopotamian civilisation (present-day Iraq), the Egyptian civilisation, and the Chinese civilisation. The Harappans had trade links with all these contemporary civilisations. In terms of geographical extent, the Harappan civilisation was among the largest. It is estimated that the size of the Harappan civilisation was almost twice as compared to either Egypt or Mesopotamia.