kathmandu was a single political unit during the early period of of malla rule but after the end of the yakshya malla it was divided into three states,namely kantipur ,patan and Bhadgaon. similarly , there were kiranti kingdoms in the east and tirhut in the south.
it is because various information media do not generally display or analyze all aspects of a subject or event. They may present only part of the story....
In order for a society to be considered a civilization, one of the first things it needs is food for the people. After all, there wouldn't be a civilization if the people didn't survive. Literature is necessary too.