350 Million Africans Speak Bantu: How the Migration Spread

At Mashava, a village 25 miles northwest of the stone ruins of Great Zimbabwe, archaeologists have pulled furnace fragments from the ground that still bear the fingermarks of the people who smoothed their clay interiors centuries ago. Some of the structures were nearly an adult's arm span wide, with walls thick enough to hold heat above 2,100 degrees Fahrenheit — hot enough to smelt iron without a single bellows, because the furnaces were built to draw air in and push it back out through a chimney on their own, according to Ars Technica's report, drawn from Knowable Magazine.

Those furnaces are one surviving trace of the Bantu-speaking peoples who began migrating out of western Africa between 6,000 and 4,000 years ago, carrying farming, livestock herding, pottery-making and metalworking into regions long dominated by hunter-gatherer communities, the outlet reported. Today roughly 350 million Africans speak one of about 500 distinct Bantu languages, stretching from Zulu in the south to Swahili in the east, and at least as many people — including many African Americans and Afro-Latinos — carry Bantu ancestry in their DNA.

What was the Bantu expansion?

It was a gradual, centuries-long spread of Bantu-speaking communities across the southern half of Africa, starting thousands of years ago and eventually reaching as far as modern-day Zimbabwe and South Africa. The migration introduced a sedentary way of life built on agriculture and metal tools to areas where it had not existed before, according to Ars Technica.

Why does Great Zimbabwe matter to this story?

Great Zimbabwe served as the capital of a thriving kingdom between roughly 1000 and 1700 AD, and its iron-smelting furnaces are evidence of the technological sophistication Bantu-descended societies reached generations after the original migration began. Ezekiel Mtetwa, an archaeometallurgist at Chicago's Field Museum of Natural History who has studied the furnaces extensively, said the engineering speaks for itself. "The number and size of these furnaces, together with the use of natural-draft technology, indicate intensive and technologically sophisticated iron production," Mtetwa said, according to Ars Technica.

How are scientists actually tracing the migration today?

Because written historical records are sparse across much of the region and research funding has been limited, researchers have had to combine disciplines rather than lean on any single one. Linguists compare the roughly 500 Bantu languages to map how they diverged; archaeologists excavate sites like Mashava for physical evidence of farming and metalworking; and geneticists study DNA to trace ancestry across populations in Africa and the diaspora. Ars Technica reports that, despite ongoing debate over the exact routes and timing, this combined approach is steadily narrowing down where the expansion began and how it moved.

Quick glossary

• Bantu expansion: The spread of Bantu-speaking peoples from western Africa across the continent's southern half, beginning 6,000 to 4,000 years ago.
• Natural-draft furnace: An iron-smelting structure designed to pull in and expel air on its own, without bellows or other human-powered airflow.
• Archaeometallurgy: The study of ancient metal-working techniques, including how societies extracted and shaped iron.

The full picture of how Bantu-speaking communities moved, mixed and built societies like the one at Great Zimbabwe remains incomplete. But the furnace fragments at Mashava, and the languages spoken by hundreds of millions of people today, are the clearest markers scientists have of a migration that reshaped the continent long before it was written down.