Fertility, the average number of children a woman has over her lifetime, has fallen worldwide. In 1950 the global average was almost five children per woman, and today it is about 2.2. The replacement level, roughly 2.1 children, is the rate at which a population stays stable over time without migration, because some children die before adulthood and a few babies are born male at more than an even rate. Countries differ widely: many with higher incomes, better education for women, widespread contraception and urban living have fallen below replacement, while some lower-income countries still have much higher rates. Falling fertility also means populations age, as fewer young people support more older adults.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.