Layalush Mersha, an Ethiopian woman in her 40s was married at the age of seven.
"He slept with me at nine," she told experts gathered for an African Union meeting on child marriage in Addis Ababa this week.
"I tried to escape, but my father-in-law put thorns around the house.
"I finally escaped after attempting suicide - with a thorn in my leg.
"It still hurts today.
"At age 13, I married again, but I could not live with him. At 18, I wed my third husband and had three children."
After leaving her abusive husband, Mersha now tries to mobilise villagers in her native Amhara province to combat child marriage.
Last month, more than 200 Nigerian girls were abducted by Boko Haram in Nigeria. Many have reportedly been forced to marry members of the Islamist sect.
The case is hardly unique, experts told a ministerial meeting of about 50 African countries in the Ethiopian capital.
Representatives of the United Nations also attended the meeting, which launched a two-year campaign against marriage under the age of 18.
"Four out of 10 girls aged between 20 and 24 years in Africa were married as children," said Martin Mogwanja, deputy executive director of the UN children's fund UNICEF.
"Progress has not come fast or far enough. The consequences of inaction will see 16 million child brides in Africa each year," said Julitta Onabanjo, regional director of the UN population fund UNFPA.
The practice is most common in Burkina Faso, Cameroon, Chad, Ethiopia, Mauritania, Mozambique, Niger, Sierra Leone, Malawi, Zimbabwe and Zambia.
It is also widespread in war-ravaged Democratic Republic of Congo, where 70 per cent of child brides end up with polygamous and abusive older men, according to UNICEF.
The AU has warned such cases are turning millions of girls into sex slaves and put millions under pressure to bear children at an early age, AU social affairs researcher Nena Tundu said.
Balkisa, a 14-year-old from Burkina Faso who is now under state protection, said in a letter read out to the AU meeting: "My brothers want me to marry. I don't want to get married. I want to continue my studies. But all my friends want me to agree to marry."
Zeinab from Niger sobbed behind her veil as she recounted her marriage at an early age.
"When I went to my husband's home, he tried to get close to me. I refused. He beat me. When I ran back to my family, they beat me and took me back to his house," said Zeinab, who is now aged around 14.
She finally bit her husband's genitals and made a definitive escape.
"It is life. It is not statistics," said Nyaradzayi Gumbonzvanda, secretary general of the Geneva-based World Young Women's Christian Association (YWCA), whose own mother married at 15.
Child marriage is rooted in traditional culture where wealth is seen to be greater with a higher number of children and survival in old age better guaranteed.
The higher cost of raising children discourages many Africans from having large families today. But impoverished parents may pressure their daughters into marrying early to receive financial compensation in the form of a dowry, experts said.
"It is an issue of resources within the family. Not every father wants to give out their child into a forced marriage. (But) they have no means. It is household poverty," Gumbonzvanda said.
The AU campaign that was launched on Thursday will lobby governments to pass policies and laws to protect girls.
Measures that will be recommended include the creation of emergency and rescue centres for girls escaping forced marriages, AU Commissioner for Social Affairs Sadiki Kaloko said.
Onabanjo said measures against poverty would reduce the practice insofar as they reduce families' need to seek dowries.
"We need to communicate messages about the risks of child marriages to the communities," Mogwanja said.