Men who cannot afford more than one wife are the catalyst for these reforms.
The Emir of Kano, Muhammad Sanusi, suggested that polygamy among the poor was linked to the rise of the Islamist militant group Boko Haram, which has been behind a violent insurgency in north-eastern Nigeria.
But it has managed to find recruits from all over the mainly Muslim north of the country.
"Those of us in the north have all seen the economic consequences of men who are not capable of maintaining one wife, marrying four," the Emir said over the weekend.
"They end up producing 20 children, not educating them, leaving them on the streets, and they end up as thugs and terrorists."
It was a brave statement that anyone who has visited the north will find hard to deny.
In many northern towns and cities groups of small children, known as "almajiris", crowd around cars stuck in traffic, begging for small change.
Marrying multiple wives is a lot less common among educated people in Nigeria but polygamy still happens in rural areas, especially in the Muslim north. [BBC] Read more
