Archaeologists have found a complete 3,200-year-old skeleton with cancer and say the discovery could help show how the disease has evolved.
The remains of the wealthy man aged 25-35 were found in a tomb close to the River Nile in Sudan by Durham University student Michaela Binder last year.
The bones showed evidence of metastatic carcinoma - cancer which has spread from where it started.
Analysis proved it came from a malignant soft-tissue tumour and spread across large parts of the body, making it the oldest "convincing" example of metastatic cancer ever found, the authors of the study, which is published in the academic journal PLOS One, said.
Researchers from Durham University and the British Museum said the discovery will help to explore underlying causes of cancer in ancient times and provide insights into the evolution of cancer in the past.
Although it is one of the leading causes of death today, it is extremely rare in archaeological finds compared to other detectable killers.
This has led scientists to conclude cancer is a product of modern lifestyles and increased longevity.
But the discovery shows cancer did exist in the Nile Valley in 1200BC.
Ms Binder, the lead author from Durham University's Archaeology Department, said: "This may help us to understand the almost unknown history of the disease.
"We have very few examples pre the first millennium AD.
"We need to understand the history of the disease to better understand how it evolved and for that it is important to find more examples."
The Austrian archaeologist added: "Our analysis showed that the shape of the small lesions on the bones can only have been caused by a soft tissue cancer even though the exact origin is impossible to determine through the bones alone."
She found the bones at the once-populated Amara West site, 750km downstream from the modern capital of Khartoum.
Co-author, Dr Neal Spencer from the Department of Ancient Egypt and Sudan at the British Museum, said: "From footprints left on wet mud floors, to the healed fractures of many ancient inhabitants, Amara West offers a unique insight into what it was like to live there - and die - in Egyptian-ruled Upper Nubia 3,200 years ago."
Tests using radiography and a scanning electron microscope provided clear imaging of the lesions on the bones, with cancer metastases on the collar bones, shoulder blades, upper arms, vertebrae, ribs, pelvis and thigh bones.
The researchers could only speculate on the cause of the cancer, with theories being carcinogens such as smoke from wood fires, genetic factors or from an infectious disease caused by parasites.
To this day, the parasitic infection known as schistosomiasis is a cause of bladder cancer and breast cancer in men in the area.