Urbanization Through History
Around 1500, fewer than 5% of humans lived in cities. By 1800, the figure was 7%. By 1950, 30%. In 2007 the world crossed 50% — the first time in human history that more people lived in cities than the countryside. The figure is now 56% and rising at roughly 0.4 percentage points a year.
Key insights
Cities pre-existed urbanization
Rome at its peak (~1 AD) likely had 1 million inhabitants — making it the largest city humanity had ever produced and not exceeded until London passed it in the early 1800s. But that scale was exceptional; the urban share of total population stayed below 10% across the world until the 19th century. Cities were small islands in agricultural seas.
Industrialization changed the math
The Industrial Revolution shifted the calculus. Factory work paid better than farming. Improving public health made dense cities survivable. Railways connected interior cities to coastal markets. Britain's urban share rose from 17% (1800) to 75% (1900). The same transition is now playing out in Sub-Saharan Africa, two centuries later and at higher speed.
Africa is the urban frontier
Sub-Saharan Africa's urban share rose from 15% (1960) to 42% (2024) and is projected to reach 60% by 2050. Lagos, Kinshasa, Dar es Salaam and Nairobi are adding more than 200,000 people a year each. The pattern differs from prior urban transitions: people are moving to cities faster than urban formal employment can absorb them, producing very large informal settlements.
World urban share 1500–2050
% of world population living in urban areas
Key Finding: The 2007 crossover was the historic 'majority-urban' milestone.
Urban share by region (2024)
% of regional population living in urban areas
Key Finding: Latin America and North America are heavily urbanised; sub-Saharan Africa and South Asia retain large rural majorities.
Methodology & caveats
What counts as 'urban'
There is no single international definition. Country statistical offices set their own urban thresholds — some by population (e.g. >2,500 in the US, >5,000 in India), some by administrative status, some by density. The UN's Demographia World Urban Areas project applies a single density-based definition; results sometimes differ from national statistics by 5–10 percentage points.
Historical reconstructions
Pre-1950 urban shares rely on city-size databases (Chandler, de Vries, Bairoch) compared against total population estimates. Definitions of 'city' varied — Bairoch used a 5,000-person threshold for Europe but the data is patchy for Asia and Africa pre-1800. The broad pattern is firm even if individual decades have wide uncertainty.
Megacities and mega-regions
Of 33 cities over 10 million today, 28 are in Asia, Africa or Latin America. Tokyo (37M) is the largest. Adjacent urban agglomerations (Pearl River Delta, NYC-Boston, BosWash) form 'mega-regions' larger than any individual city — but statistical conventions usually treat them as separate jurisdictions.