Every year the Nelson Mandela Foundation invites prominent figures to Johannesburg to discuss pressing social matters affecting the global community for its 16th annual Nelson Mandela Lecture. This year, that figure is none other than former US president Barack Obama.

This year's theme is "Renewing the Mandela Legacy and Promoting Active Citizenship in a Changing World." The lecture will focus on"creating conditions for bridging divides, working across ideological lines, and resisting oppression and inequality," said the foundation in a statement.

Former speakers include Kenyan Nobel Laureate Wangari Maathai, Archbishop Desmond Tutu, Bill Clinton, Bill Gates and former UN secretary-general Kofi Annanto name a few.

"We thought who can [better] represent the legacy of Madiba than the person who we believe took on the baton when he became president of his own country," said Sello Hatang, the foundation's chief executive. Adding that the foundation wanted someone of "African heritage" to give this year's address.

The lecture is a way to celebrate both men's outstanding legacies. "We hope that it will again be a significant moment for the two legacies to join," added Hatang.

Obama will deliver his lecture on July 17 at Ellis Park Arena in Johannesburg, just one day ahead of what would have been Mandela's 100th birthday.