“What happened to the great civilisation that rose and flourished in the heart of Southern Africa more than 1,000 years ago?”

Deep in the heart of southern Africa, on the Zambezi River, a great civilisation rose in the 8th century. Its magnificent walled city stood as testament to a thriving, sophisticated culture called Great Zimbabwe. It was larger than medieval London 500 years later, and rich in gold and ivory.

Mysteriously, by the 10th century the population had disappeared. Rediscovered in 1871, the findings at the ruins reveal the existence of this high civilisation. But what happened to it?

In this documentary we journey back to 1871 when German geologist Carl Mauch, obsessed by rumours of mysterious ruins, survived kidnapping and robbery to discover an enormous enclosure, built from 30 ft high stone walls: the remains of Great Zimbabwe.

Carl Mauch was a geographer and gold digger and was the first Westerner to find extensive ruins in this unexplored and uncharted part of Africa. He believed he had found the remnants of a great, lost, white civilisation, not something built by the natives. It then dawned on him that he might have discovered the Queen of Sheba’s palaces and King Solomon’s mines!

Mauch travelled back to Germany and published his finding. His discovery became known as the ‘Riddle of Rhodesia’.

His theory stood as fact until 1928, when the formidable, English archaeologist Gertrude Caton-Thompson excavated the site with her all-female team and put the world’s understanding of ancient Africa on a new footing.

Gertrude was a passionate explorer and archaeologist, as well as a very professional scientist. She used a plane to explore the excavations from the air and she made some startling discoveries.

She unearthed proof that Great Zimbabwe had been built by a native African creation, turning racist preconceptions about Africa on their head. Proof that high civilisation could arise in black Africa, refuting the myth of white racial superiority.

This documentary is part of the highly acclaimed ‘Treasure Seekers’ series, produced for National Geographic.