World Christian Database

Cities and Christians

Christians AD 33 to AD 1800

Estimates of the number of Christians by UN Region at significant dates from AD 33 to AD 1800 are included for the first time this quarter in a single new query Christians (in millions) by Region AD 33 to 2050 on the Chronology page. The query displays global figures by default; simply change the criteria to see data for each UN region.

Christian figures are also broken down by major tradition: Orthodox, Catholic, Protestant, and Independent. The numerical growth of Protestants by Major Region in this 500th anniversary year of the Reformation can thus be viewed at key dates across the 500 years since 1517.

The Chronology page itself provides much of the documentation and historical context for these estimates by documenting the significant events in Christian history which sparked growth or decline across the centuries in each country and region. The concepts are fully discussed in Part 7 of World Christian Trends (2001) where original graphs and data include brief explanations of key turning points; for example, at the global level:
  • AD 30 Jesus preaches good news in Palestine
  • 300 Church grows rapidly in Roman Empire
  • 500 Goths, Visigoths accept Christian message
  • 700 Islam spreads across formerly Christian lands
  • 1200 Friars spread message across Europe
  • 1350 Black Death kills 75 million in Europe and Asia
  • 1400 Tamerlane wipes out Church of the East
  • 1500 Roman Catholic missions to Africa, America, and Asia
  • 1800 Protestant missions begin
  • 1950 Tribal religionists convert to Christianity in large numbers.

Definition of 'Cities'

The definition of the geographic boundary which constitutes any particular city can vary widely between countries and over time. Growing cities for example at some point incorporate what were separate cities, which then become identified as a single city. Documenting the population of such cities thus largely depends on which sub-cities are included in the definition.

The WCD Cities listing now consists of the UN's 1,785 Urban Agglomerations each with over 300,000 population in 2015. Future updates will also be in accordance with the UN Population Division's World Urbanization Prospects revisions. Standardizing to the UN's definition of each city allows for more precise estimates and documented boundaries.

WCD's definition of 'Metro' has now changed from 'urban areas over 50,000' to 'urban areas over 300,000' to align with the UN's listing of Urban Agglomerations.

An archive of 8,537 WCD cities (level 1) and sub-cities (level 2) in 2010 down to 50,000 population is also available, but note that because the definition of any city may have changed between the archive and the new listing they should not be used together.

On the City/Province page see the default city listing for the latest Christian data on cities over 300,000, and see the archive listing for 2010 data on cities down to 50,000.