An old incident of adultery recently halted construction of a bridge that would connect two Yoruba communities across a wide river valley.

The west bank group refused to cooperate, harboring a deep grudge against the east bank community because one of the latter's members had seduced the wife of a west bank member.

"It's me who had to step in and reconcile the two groups," said the oba, or king, of Oshogbo, Iyiola Oyewale Matanmi III. "I am the father of both communities, and they listened to me."

Matanmi is 15th in this city's line of blood-related Yoruba kings that stretches back to Oshogbo's founding in the 17th century. They all claimed, as Matanmi does today, direct descent from the legendary progenitor of all Yorubas and founder of the original Yoruba city-state of Ile-Ife, Oduduwa.

Matanmi is an unusual figure in Nigeria because he is the only traditional ruler who holds a state-level Cabinet post as minister-without-portfolio in the Oyo State Executive Council.

"My people always find it difficult to divorce themselves from tradition," Matanmi said. "I represent the other obas [in Oyo State], and the obas don't have to lobby with the politicians because I take their positions in the Cabinet."

It is the powerful pull of tradition wrapped up in the role of obas such as Matanmi that still gives them crucial influence in day-to-day life.

"I am first and foremost the crown ruler of Oshogbo," Matanmi said in an interview in the high-ceiling throne room of his palace. "Once an oba is crowned, the community's regard for him is above everything else except god."

In contemporary Nigeria, however, the power of the obas has diminished.

First the British subjected the obas to colonial rule at the end of the 19th century. With independence in 1960 the obas entered politics, taking sides in local disputes while the country was wracked by political violence and riots. The obas lost much of their traditional prestige at that time.

"During the crisis of the 1960s," said Prof. Tunde Adeniren, University of Ibadan political science professor, "the only institution that people could turn to was that of the traditional rulers, but they were politicized and, therefore, discredited. But even today, you can't exclude traditional rulers altogether if you want to get anything done."

Matanmi was voted onto the throne by the elders' council four years ago at age 38 and gave up his business as a chartered accountant.

Matanmi is a Moslem, but as oba he must preside over the traditional rites connected with the Yorubas' animist religion.Animism is the belief that all natural phenomena have souls.

"There is no conflict between my Moslem beliefs and the traditional beliefs," said Matanmi. "As oba of Oshogbo, I must ensure the peace and well-being of Christians, Moslems, believers in traditional religions as well as Yorubas and non-Yorubas living in city."