LAGOS, Nigeria - It was a typical husband-wife argument. She wanted to visit her parents. He wanted her to stay home.
So they settled it in what some here say is an all-too-typical fashion, Rosalynn Isimeto-Osibuamhe recalled of the incident in December 2001. Her husband, Emmanuel, followed her out the door. Then he beat her unconscious, she says, and left her lying in the street near their apartment.
Joao Silva for The New York Times
A woman played with her child in her room in a shelter for abused women in Lagos, Nigeria.
Joao Silva for The New York Times
Rosalynn Isimeto-Osibuamhe, who has broken with her husband, sang at a church service in Lagos.
Ms. Isimeto-Osibuamhe, then 31 and in the fifth year of her marriage, had broken an unwritten rule in this part of the world: she had defied her husband. Surveys throughout sub-Saharan Africa show that many men - and women, too - consider such disobedience ample justification for a beating.
Not Ms. Isimeto-Osibuamhe. A university graduate and founder of a French school, she packed her clothes and walked out as soon as she got back from the hospital. So far, although her resolve sometimes wavers and she does not want a divorce, she has not gone back.
"He doesn't believe I have any rights of my own," she said in an interview outside her French classroom. "If I say no, he beats me. I said: 'Wow. That is not what I want in life.' "
Women suffer from violence in every society. In few places, however, is the abuse more entrenched, and accepted, than in sub-Saharan Africa. One in three Nigerian women reported having been physically abused by a male partner, according to the latest study, conducted in 1993. The wife of the deputy governor of a northern Nigerian province told reporters last year that her husband beat her incessantly, in part because she watched television movies. One of President Olusegun Obasanjo's appointees to a national anticorruption commission was allegedly killed by her husband in 2000, two days after she asked the state police commissioner to protect her.
"It is like it is a normal thing for women to be treated by their husbands as punching bags," Obong Rita Akpan, until last month Nigeria's minister for women's affairs, said in an interview here. "The Nigerian man thinks that a woman is his inferior. Right from childhood, right from infancy, the boy is preferred to the girl. Even when they marry out of love, they still think the woman is below them and they do whatever they want."
In Zambia, nearly half of women surveyed said a male partner had beaten them, according to a 2004 study financed by the United States - the highest percentage of nine developing nations surveyed on three continents.
In South Africa, researchers for the Medical Research Council estimated last year that a male partner kills a girlfriend or spouse every six hours - the highest mortality rate from domestic violence ever reported, they say. In Harare, Zimbabwe's capital, domestic violence accounts for more than 6 in 10 murder cases in court, a United Nations report concluded last year.
Yet most women remain silent about the abuse, women's rights organizations say. A World Health Organization study has found that while more than a third of Namibian women reported enduring physical or sexual abuse by a male partner, often resulting in injury, six in seven victims had either kept it to themselves or confided only in a friend or relative.
Help is typically not easy to find. Nigeria, Africa's largest nation with nearly 130 million people, has only two shelters for battered women, both opened in the last four years. The United States, by contrast, has about 1,200 such havens. Moreover, many women say wifely transgression justify beatings. About half of women interviewed in Zambia in 2001 and 2002 said husbands had a right to beat wives who argue with them, burn the dinner, go out without the husband's permission, neglect the children or refuse sex.
To Kenny Adebayo, a 30-year-old driver in Lagos, the issue is clear-cut. "If you tell your wife she puts too much salt in the dinner, and every day, every day, every day there is too much salt, one day you will get emotional and hurt her," he said. "We men in Africa hate disrespect."
Nigeria's penal code, in force in the Muslim-dominated north, specifically allows husbands to discipline their wives - just as it allows parents and teachers to discipline children - as long as they do not inflict grievous harm. Assault laws could apply, but the police typically see wife-beating as an exception. Domestic violence bills have been proposed in six of Nigeria's three dozen provinces but adopted in just two.
Women's rights activists say that the prevalence of abuse is emblematic of the low status of women in sub-Saharan Africa. Typically less educated, they work longer hours and transport three times as much weight as men, hauling firewood, water and sacks of corn on their heads.
Ms. Isimeto-Osibuamhe does not fit that standard profile. Articulate, with a fashionable haircut and a sociology book in her bag, she speaks in a confident, even assertive tone of voice. Her diary is full of plans for various projects she hopes to undertake. "I am an organizer," she said in a series of interviews. "I am a leader."
But that did not save her from a seemingly endless string of beatings during her eight-year marriage to her husband, Emmanuel.
By Nigerian standards, Ms. Isimeto-Osibuamhe said, her parents were progressive. Her father occasionally beat her mother, but he also encouraged his daughter, the oldest of seven children, to pursue her studies and, later, her careers as a marketing executive, French teacher and host of a French educational television show.
She was only about 16 when she met Emmanuel. Like her, he went on to graduate from a university, specializing in accounting. Slim and handsome, he slapped her only once during their long courtship, she said. She thought it was an aberration.
It wasn't. Now 35, Ms. Isimeto-Osibuamhe says that Emmanuel beat her more than 60 times after she married him in 1997. He beat her, she says, while she was pregnant with their son, now 6. He threw a lantern at her. He held a knife to her head, she said, while a friend pleaded with him not to kill her.
Emmanuel Osibuamhe, 36, now says he was wrong to beat his wife. But in a two-hour interview in his office, which doubles as barber shop, he insisted that she drove him to it by deliberately provoking him. Pacing the floor in freshly pressed pants, polished shoes and yellow shirt, he grew increasingly agitated as he recalled how she challenged his authority.
"You can't imagine yourself beating your wife?" he said. "You can't imagine yourself being pushed to that level? But some people just push you over the edge, and you do things that you are not supposed to do."
"For God's sake," he added. "You are the head of the home as the man. You must have a home that is submissive to you."
To him, that means accepting that he is the head of the household and makes the final decisions. It also means that all property be in his name and that his wife ask his permission before she visits her family, he said.
When Ms. Isimeto-Osibuamhe eventually sought help, others only seemed to support her husband's view. She went to the police. "They told me I am not a small girl," she recalled. "If I don't want to be married, I should get divorced."
She told her father-in-law. He advised her that "beating is normal."
She told her local pastor, who counseled her that "I shouldn't make him so angry," telling her "whatever my husband says, I should submit."
She found support, finally, at Project Alert on Violence Against Women, a nonprofit organization that runs one of Nigeria's two shelters. She lived at the shelter for weeks. She titled her statement detailing the violence "A Cry for Help."
Briget Osekwe, the senior program officer, said the group's files contained 200 cases like Ms. Isimeto-Osibuamhe's. Even some women who are economically independent like Ms. Isimeto-Osibuamhe, she said, are loath to divorce their husbands for fear of social disgrace.
"In this society, a woman must do everything she can to make her marriage work," said Josephine Effah-Chukwuma, who set up Project Alert in 1999. "If it fails, the woman gets the blame."
Since she moved out, Ms. Isimeto-Osibuamhe said, her husband has hit her a dozen times, once knocking her to the floor of their church. She is torn over whether it is possible for him to change. She worries about how she will raise her son, now living with his grandparents, should she divorce. "Should I stay because of the baby and then get killed?" she asked. But at another point she asked a reporter to make sure that in any account of her story, her last name would be hyphenated to include his.
Her diary is filled with notes on how his views are wrong. "Marriage to you: A slavery relationship!" she wrote this January.
She has now found a new outlet as the creator and host of a local television show on domestic violence. After the first program was broadcast, she said, she was deluged with calls from women like herself. She hopes to pursue their cause through a little foundation she has formed called "Happy Family."
"An African man believes his wife is like a piece of property, is like a car, is like a shoe, is like something for him to trample on," Ms. Isimeto-Osibuamhe said. "Our men need education."
So do "our mothers, our fathers, our sons," she added. "The whole society needs to be overhauled."