The Human civilizations and cultures in the remote past developed independently and separately in their isolated regional/geographical settings as per their natural situations. The human mind has always been interacting and negotiating with its surroundings and developing its belief systems and social practices, so you come to know about various cultures of anteriority. Earlier, the contact between such cultures was meager and confined to some adventurous traders who were able to establish contact with distant areas, for example, you know about trade links even between the proto-historic Indus and its contemporary Mesopotamian civilizations. With the conquering of the alien regions and peoples by some ambitious leaders and the emergence of vast political empires, however, larger areas were knit together, which also opened the gates of cultural interaction and progress of synthesized cultures and civilizations, expansion of trade links, and so on, in broader areas. Furthermore, with the emergence and progress of new religious movements, Buddhism, Christianity, and Islam in particular, a greater number of people came together under their shades of religious culture, widening the boundaries of humanity. Thus, humanity, at large, has always been aspiring for expanding and widening the area of its activities in harmony and peace, despite the experiences of conflicts and wars quite contrary to it.