This is an attempt to display five millennia of empire size data
(primarily that collated by Rein Taagepera)
as a Sankey chart.
In particular, the chart below has the following characteristics:
Empires and dynasties are grouped and colour-coded by geographical region.
Time flows from top to bottom (logarithmically).
Horizontal positions within the chart approximate to longitudes of the empires.
Horizontal widths equate to land area (measured in Mm² or millions of square kilometres).
Dotted lines represent independence of large nations.
The table below presents the raw data used in the chart above.
Points of peak area are highlighted.
Cumulative sizes are estimates of the empire's land area multiplied by the number of years that area was held (measured in Mm²y).