By Andrew Walker
BBC News, Osogbo, Nigeria
Mrs Wenger resurrected the traditions of the river-god Osun
Half a lifetime ago, Susanne Wenger dedicated herself to reviving the traditions of the pre-Christian Yoruba gods, "the orishas", and left Austria to make Nigeria her home.
The frail 94-year-old artist, with one seeing eye, has been a driving force in Osogbo town, where she is in charge of the sacred grove, a place where spirits of the river and trees are said to live.
In an upstairs room of her house, surrounded by carved wooden figures of the gods, she receives well-wishers and devotees, who she blesses in fluent Yoruba.
When she arrived here, she found traditional culture in abeyance, all but destroyed by missionaries who branded it "black magic" or "juju", a word Mrs Wenger reviles.
Friends paint a picture of a dedicated, tough and far-sighted leader who has helped revive a culture thought destroyed by Christian and Muslim evangelists, and secured protection for one of the Yoruba tradition's most sacred sites.
But she is very humble about her achievements.
Osun-Osogbo Sacred Grove Festival
"Osogbo is a creative place, it is that by itself, it didn't need me," she says.
Followers say she has channelled the river-god Osun into her body, learning the knowledge of pre-Christian deities like no other European has ever done.
Orisha worship is a controversial belief. In the past it involved human sacrifice and there are rumours that still happens at secret shrines elsewhere in the country.
Devotees of the orishas can worship either good or evil gods in order to get what they want.
But thanks to Mrs Wenger, the town's annual festival of Osun has grown in size and popularity and thousands of Yorubas come every August to renew their dedication to the river-god.
Mrs Wenger arrived in Nigeria in 1950 with her then husband, the linguist Ulli Beier and travelled widely in south-western Nigeria.
Maybe you can call Susanne our saviour
Sangodare Gbadegesin Ajala
In 1957, she fell ill with tuberculosis in an epidemic in which many thousands died.
Friend Ajani Adigun Davies says Mrs Wenger believes the illness was a kind of sacrifice, in return for the knowledge she was receiving about the gods.
"The Yoruba beliefs all depend on sacrifice, that you must give something of value to get something of value, you must suffer pain to gain knowledge," he says.
In her early years in Nigeria she met Adjagemo, a high-priest of creator-god Obatala.
"He took me by the hand and led me into the spirit world," Mrs Wenger told a French documentary maker in 2005.
"I did not speak Yoruba, and he did not speak English, our only intercourse was the language of the trees."
She divorced her husband and moved in with Adjagemo in Osogbo, where she resolved to live for the rest of her life.
Mrs Wenger believes that the spirit world has long been neglected by Western culture, and spirits can appear to anyone as long as they are willing to accept them.
"You need special eyes to see them," she says.
Enemies in churches and mosques have tried to smash her sculptures of deities and burn down the forest that shelters them.
But artist Sangodare Gbadegesin Ajala, Mrs Wenger's adopted son, says many local people accepted her eagerly.
Susanne's knowledge of the behaviour and character of all the deities means she has actually become Yoruba now
Former curator Ajani Adigun Davies
"Maybe you can call Susanne our saviour," says Mr Ajala, now the high-priest of Sango, the lightning-god.
"Was Christ an African? Muhammad was an Arabian. Why can't our saviour be European?"
The first time he met her was the day of his initiation into the cult of Sango, when he was 11.
His father was an unapologetic devotee of the old gods, and refused to let his child be baptised or go to schools run by Christians or Muslims.
But Mr Ajala wanted to learn to read, and he thought a white woman would let him.
"I saw some children reading books, and I wanted to be able to go to school to read these stories."
But six months after he moved in with Mrs Wenger, he asked her if he could go to school.
"She shouted: 'No! you cannot go to school, they will turn you into a Christian and your life will be over!'" he remembers.
Mr Ajala is still illiterate, but has a deep knowledge about the traditions of Yoruba spirit gods and says his adopted mother has made him see how important it is that Yoruba traditions have been preserved.
Yet he is now working to build a school where children can go and receive an education and also learn about the traditions of the orishas.
'Tug of war'
Mrs Wenger's ideas about the preservation of the forest have become central to the survival of the traditional beliefs.
Mr Adigun Davies, a former curator with the government museums directorate who first met Mrs Wenger in 1989, says the battle to save the grove was a "tug of war".
He recalls her lying down in the path of a bulldozer brought by a man who bought the grove from a relative of a traditional leader and wanted to build a house on the land.
"It's a disgrace to the Yoruba that the person who came to save our culture was a European," he says.
"But Susanne's knowledge of the behaviour and character of all the deities means she has actually become Yoruba now."