Which one of the following is the first urban settlement in the world to reach a population size of one million (million-plus city) ?

London was the first urban settlement in the modern era to reach a population size of one million, achieving this milestone around 1810 . This rapid growth was primarily driven by the Industrial Revolution and the demographic transition, which saw falling death rates and rising birth rates in England . While some ancient cities like Rome or Baghdad are hypothesized by historians to have reached one million inhabitants in antiquity (as early as the 1st century B.C.E.), these figures are often debated due to the lack of formal census data [2]. In the context of modern urbanization trends, London is universally recognized as the first 'million-plus' city, followed by other major centers like New York, which later became the first to reach ten million [2]. By 1851, Britain had become the first predominantly urban society, with over half its population living in towns .

Sources

1. [1] https://education.nationalgeographic.org/resource/history-cities/
2. [2] https://en.wikipedia.org/wiki/List_of_largest_cities_throughout_history