The heirs: civilizations that grew from the six

Civilization was invented six times, in Sumer, Egypt, Peru, the Indus Valley, China, and Mexico. Every civilization after those six received it rather than invented it.

These cultures built some of the most famous sites in history, but each one took its foundations from one of the six. None of them invented cities, writing, or government a second time. This list continues past the first civilization and into written history, because that is where the inheritance becomes visible. Two entries near the end, the Vikings and the Mongols, are not civilizations by the archaeological definition. They are included because both moved goods, people, and ideas between civilizations on a scale nobody else matched.

Kerma, Sudan, about 2500 BCE. The second city-building civilization in Africa, on the Nile upstream from Egypt. It later became the kingdom of Kush, which conquered Egypt and ruled it as its 25th dynasty. Inherited from Egypt.
Minoans, Crete, about 2000 BCE. The first civilization in Europe, with palaces at Knossos. Their writing has never been decoded. Inherited from Sumer and Egypt through the Near East.
Mycenaeans, Greece, about 1600 BCE. These are the Greeks of the Trojan War story. They used an early form of Greek writing. Inherited from the Minoans.
Phoenicians, Lebanon, about 1200 BCE. Sea traders who founded Carthage. They spread the alphabet that Greek and Latin came from, and that this page is written in. Inherited from Sumer through the Levant.
Classical Greece, about 800 BCE. Independent city-states, written philosophy, and formal mathematics. Inherited from the Minoans, the Mycenaeans, and Egypt.
Rome, 753 BCE. Roads, concrete, aqueducts, and a written legal code, across three continents. Inherited from Greece and the Etruscans.
Persia, 550 BCE. The first empire to govern many different peoples under one administration, with a road network and an imperial postal service. Inherited from Sumer through Mesopotamia.
Monte Albán, Mexico, about 500 BCE. The Zapotec capital, built on a mountain top that was levelled first. It holds some of the earliest confirmed writing in the Americas. It took the calendar and the monument-building tradition from the Olmec.
Nazca, Peru, about 100 BCE. They made the Nazca Lines, drawings on the ground up to 400 m long that can only be seen as a whole from the air. The lines lie near their religious capital, Cahuachi. Their underground water channels still work in the desert today.
Teotihuacan, Mexico, about 100 BCE. At its largest it was one of the biggest cities on Earth, with more than 100,000 people. Its largest building, the Pyramid of the Sun, covers almost the same ground as the Great Pyramid of Giza, at about 225 metres along each side against 230. It stands about half as high and it holds less than half as much material. Nobody knows for certain who built it. The Aztecs arrived long after it was abandoned and named it the place where the gods were created.
Moche, Peru, about 100 CE. The best metalworkers and the finest ceramic artists in the ancient Americas. Their mud-brick pyramid Huaca del Sol used more than 130 million bricks. The royal tomb at Sipán is one of the richest burials ever excavated in the Americas.
Aksum, Ethiopia, about 100 CE. A trading empire on the Red Sea with its own writing system, which is still used to write Ethiopian languages today. It began in the first century CE and was at its strongest between the fourth and sixth centuries. Inherited from Egypt and southern Arabia.
Maya, Mexico and Guatemala, about 250 CE. The only writing system of the ancient Americas that has been fully decoded. They had a detailed calendar, and they used zero as a placeholder in written numbers. Inherited from the Olmec.
Tiahuanaco, Bolivia, about 550 CE. An empire 3,850 m above sea level, near Lake Titicaca. Its stone blocks were cut so precisely that they fit together without mortar. Its farming system of raised planting beds produced more food per field than modern farming methods do on the same ground.
Vikings, Scandinavia, 793 to 1066 CE. Norse farmers and raiders. Their ships sat high in the water, which let the same boat cross open ocean and travel up shallow rivers. They reached Baghdad in the east and Newfoundland in the west. Their date in North America is now exact. Trees were cut at L'Anse aux Meadows in 1021 CE, 471 years before Columbus. That site was probably a temporary base rather than a settlement, because no graves, tools, fields, or animal pens were found there. The Vikings are not a civilization by the archaeological definition, because at the start they had no cities and no state. They were the most effective long-distance travellers of their time. Inherited from Rome and the Near East through European farming.
Khmer, Cambodia, 802 CE. They built Angkor, and an engineered water system held the whole place together. Laser scanning from the air, combined with modelling, gives 700,000 to 900,000 people in the wider Angkor region at its peak in the 13th century. Those people were spread thinly across a landscape of temples, earth mounds, and reservoirs, not packed into a walled city. That is why Angkor covers more ground than any other settlement built before industry. Inherited from India.
Cahokia, United States, about 1050 CE. The largest city north of Mexico before 1800, with 10,000 to 20,000 people at its peak between 1050 and 1150. Its main earth mound, Monks Mound, covers about the same ground area at its base as the Great Pyramid of Giza, and the distance around that base is greater than at the Pyramid of the Sun in Teotihuacan. Inherited from Mexico and Central America.
Great Zimbabwe, about 1100 CE. A stone city built without mortar, which traded gold to the Indian Ocean coast. People settled there from about 1000 CE, and it became the capital of its kingdom in the 13th century. The population is disputed. The older figure was 20,000 at its peak. A later study concluded that the total number of people who lived there across the whole 800 years of occupation is unlikely to have passed 10,000. Inherited from the trade networks of East Africa and the Indian Ocean.
Mongols, 1206 CE. Herders who lived in tents and built no cities, and who conquered the largest connected land empire in history. They then protected the trade routes that crossed it. Inherited from the grassland cultures that the horse made possible.
Aztec, Mexico, 1428 CE. Their capital Tenochtitlan held 200,000 people on an island in a lake, fed by farm plots built on rafts in the shallow water. Inherited from the Olmec through Teotihuacan.
Inca, Peru, 1438 CE. An empire of 12 million people, connected by 40,000 km of mountain roads, and administered with knotted cords instead of writing. Inherited from Norte Chico, the Moche, and Tiahuanaco.