NAIROBI, Kenya — Here is the modern face of the Africa-China diptych: standing next to half-built roads across Africa — sometimes in the most far-flung places, in a Congolese jungle, or a desert in Niger — is the Chinese foreman, wide-brimmed hat on his head, cigarette dangling from his mouth.

It has become an oddly familiar sight but there is a more ancient aspect to the Africa-China relationship, one that might date back 600 years or more according to an international team of archaeologists that has started work here in Kenya.

Across the continent China is re-building neglected African infrastructure in exchange for natural resources to fuel its own domestic growth. In 2008 China’s trade with Africa was worth $107

billion, more than the United States and 10 times more than imports and exports between China and Africa were worth at the start of this century.

Last year Chinese Prime Minister Wen Jibao signed a series of multibillion dollar deals and then offered $10 billion in cheap loans to African governments.

On Kenya’s Swahili coast, a place of barefoot beauty, the talk of billions spent on modern infrastructure seems incongruous, an anachronism.

A little to the north of the popular tourist town of Malindi — one mile by foot along the white sand beach, six miles by car along the potholed inland road — is Mambrui. It is the suspected site of an

ancient Swahili kingdom, home of the sultan of Malindi and destination of Zheng He, a 15th century Chinese admiral, merchant, emperor’s emissary, explorer and eunuch.

“Malindi is a very important point between China and Africa trade,” said professor Qin Dashu of Peking University’s School of Archaeology and Museology who is leading a team of nine Chinese and six Kenyan archaeologists. China’s government is spending $3 million on the three-year long project.

Excavating the site of a 16th-century cemetery, they have already found fragments of Chinese porcelain in the tombs. “That is evidence of an ancient China-Africa relationship,” said Qin.

“Chinese and African trade was initiated around the middle of the eighth century and developed very fast reaching its first peak around the ninth to 10th centuries and from that time we can prove that Chinese objects and goods had already reached East Africa,” he said.

However, while goods may have made their way overland to the east, the first Chinese explorer did not arrive until hundreds of years later.

“Ninth-century Chinese texts talk of Malindi,” said Qin, “but we believe that Zheng He was the first [Chinese] person to come to East Africa.”

Zheng He was born to a Muslim family in 1371 but was captured by the Ming army at age 11 and made a eunuch. He rose in favor, eventually becoming admiral of a huge fleet that embarked on seven separate expeditions between 1405 and 1433, the year of Zheng He’s death.

Each expedition involved hundreds of ships and tens of thousands of sailors. Diplomacy and trade were the goals but Zheng He’s ships were also well-armed and ready to fight. His fifth voyage took him through the Strait of Malacca and across the Indian Ocean to East Africa where Zheng He traded Chinese porcelain, gold, silver and silk for ivory and exotic wildlife like ostriches, giraffes and zebras.

Zheng He’s arrival in Malindi in 1418 would predate the first European explorers by decades. In Malindi a stone cross still stands erected by the Portuguese explorer Vasco da Gama who arrived in 1499.

To prove the stories true, the Museum of China is sending an additional team of specially trained underwater archaeologists to look for one of Zheng He’s sunken ships, which capsized close to the island of Lamu, according to oral traditions.

They will have their work cut out for them. The ocean topography here tends to follow the pattern of a shallow, crystal-clear lagoon, a coral reef and then a steep drop down a rock shelf into deep ocean. If the wreck lies in waters deeper than 80 meters it will be impossible to excavate.

While discovering Zheng He’s junk would be a tremendous prize it is not the only proof needed of a long trade relationship between Africa and China.

“In Mambrui we are already finding porcelain dating back to the late 14th and early 15th centuries. We hope to link that porcelain from ancient Malindi to particular kilns in China,” said Herman Kiriama, head of the department of coastal archaeology at the National Museums of Kenya and leader of the Kenyan team.

That matters, said Kiriama, because it might reveal something of the relationship between the Chinese emperor and the East African sultan.

Assessing the quality of the pottery found in Mambrui and tracing the fragments to the emperor’s kilns would show the porcelain was imbued with a greater value than simple trade goods. That would suggest a relationship based on parity and mutual respect rather than base economics or straight exploitation, said Kiriama:“It will show us how the emperor valued the sultan, that he had a very special regard for this person.”