NepalRajya paints historical rule onto present-day district shapes, the same trick every popular historical atlas uses — the alternative, drawing precise borders for every year of the last 2,800 years, isn't something anyone actually knows. Drag the timeline and every district recolors to whoever held it that year, resolved from a dataset of rule intervals rather than hand-drawn snapshots.
Nepal's pre-unification fragmentation is modeled properly: the Baise and Chaubise hill confederacies, the three rival Malla courts of the Kathmandu Valley, the Sen kingdoms, and Mustang's two-century run as a tributary vassal that outlasted the monarchy itself. Where a name and a date are well documented — a Shah king, a Rana prime minister, Bhupatindra Malla's Bhaktapur — the atlas names them and dates their reign, rather than leaving every district a single anonymous color for its whole ruling era.
Modern district shapes are retrofitted onto history that predates those districts by over a thousand years — a defensible simplification, not a claim that the Achham of 800 CE had this exact outline. Several smaller hill principalities (Manang among them) still share a single generic label because no source gives a confident separate date for them. Pre-Licchavi Kathmandu Valley history compresses centuries of chronicle tradition (the Gopalarajavamshavali's Gopala and Mahispala kings) into one dated span, flagged as such rather than presented with false precision.
Between roughly 1789 and 1816, the Kingdom of Nepal briefly held Kumaon, Garhwal and a strip of Sikkim now in India — about 1.4x today's area, not the “3x” figure that circulates informally. Those regions appear on the map only for the years Nepal actually ruled them, approximated by modern Indian district boundaries since no present-day Nepali shapes exist for territory that hasn't been part of the country in two centuries.