ANTI-SLAVERY INTERNATIONAL, a London-based advocacy group, has hailed what it says is the first-ever conviction in Niger of a man for slavery. “A 63-year-old man has been sent to jail for four years for enslaving a girl as a ‘fifth wife’, a practice whereby girls of slave descent are sold by Tuareg ‘masters’ to wealthy men who view the purchase of young women as a sign of prestige,” reports the group, which was founded in 1839 as the Anti-Slavery Society and claims to be the world’s oldest human-rights body.

Girls in Niger sold as slaves are known as “fifth wives” because Islam as practised in Niger and in neighbouring northern Nigeria permits a man to have four wives, says the organisation. No formal marriage takes place and the girls are treated as property, often suffering abuse, including rape.

There are reckoned still to be 40,000 slaves in Niger. Many are born into slavery because their mother was a slave. They grow up under the direct or indirect control of slave-owning “noble” families or “masters”, who make them herd animals, control their nomadic migrations, and arrange their marriages without their consent. They are unpaid.

Though slavery was criminalised in Niger 2003, this is the first conviction for it, says Anti-Slavery International. The state authorities often deny slavery’s existence, and rarely pursue the cases brought to their attention by anti-slavery campaigners, it adds. But this recent case, it hopes, “will be a catalyst for similar cases to be taken through the courts with similar conclusions.” There are still 20m slaves worldwide, says the organisation.