Compiled history
Population figures pieced together from historical records and censuses, roughly 1800 to 1949.
In short
This is the middle tier of confidence used across the site: not a full modern estimate, but sturdier than a reconstruction from before written records existed.
How it's built
Before international statistical agencies existed, population figures came from national censuses, colonial administrative records, church registers and similar historical documents — compiled and cross-checked long after the fact by researchers, rather than collected as one coordinated system.
Gapminder v7 is the source we use for this era. Its team assembled records country by country, filling gaps with interpolation and scholarly estimates where direct documentation was missing.
Note Coverage varies a lot within this period. A well-documented census year in one country can be far more reliable than a rough estimate for a country with no census at all before 1950.
Where it sits in the confidence ladder
Why it matters here
Every chart on this site marks 1800 and 1950 as source seams — exactly where compiled history begins and ends. On the canvas it's drawn as a 75%-tint fill with a solid edge, one step more solid than the lighter, dashed fill used for reconstruction just before it.
This visual encoding matters because a population jump or dip at a seam year may reflect the change in data source rather than a real demographic event. Seam lines are there to remind you to treat numbers on either side with that in mind.
Frequently asked questions
What is compiled history in population data?
Compiled history refers to the middle tier of population data quality — figures from roughly 1800 to 1949 assembled from national censuses, colonial administrative records, church registers, and scholarly estimates. They are real records, not indirect reconstructions, but collected under very different standards across countries and time periods.
Why does compiled history cover 1800 to 1949 specifically?
Around 1800, enough countries had begun conducting regular censuses that population figures could be assembled from primary documents with reasonable confidence. 1950 is when the UN World Population Prospects introduced a coordinated international estimation system. The 150 years in between are compiled history.
How reliable are compiled history figures?
Reliability varies enormously. A well-documented country with regular censuses from the 19th century (such as Sweden or the UK) may have figures nearly as solid as modern estimates. A country with few or no censuses before 1950 may have figures that are little better than educated guesses. The source band on the chart marks this era with a lighter fill and a solid edge — one visual step above reconstruction. The Clio Infra database is another scholarly resource for pre-1950 population and demographic data, built from archival records across more than 180 countries.
Which dataset provides compiled history on this site?
Gapminder v7 is our primary source for the compiled history era (1800–1949). Gapminder cross-checks national census records, colonial administrative data, and scholarly estimates to produce a consistent series for each country. It is produced by the Gapminder Foundation and is openly licensed under CC BY 4.0. Full documentation is available on the Gapminder population data page.