I think what Aryal suggested about Newar being mongolian left out may be the link between the Earlier rulers of Nepal ,The Kiratis, today's Rai n limbus( the earliest and the longest ruler of Nepal who later on eastablished theirkingdoms in the eastern side of nepal until the shah king's unification) and not the rulers from mongolia. 'Another remarkable event during the kiratas period is the coming of Gautam Buddha in the time of the seventh king. The Buddha supposedly spent time in Patan, where he elevated the blacksmith caste to goldsmiths and bestowed upon them the name of his own clan, Sakya.'- abstacted from a history website. NEWAR are the original natives of this land having it's link to the earliest inhabitants.Some also give a theory which says ' Newar was term originated to refer to people from kathmandu valley-at a time of valley blockage - which later on became a 'tribe' on it's own ."