Former President Olusegun Obasanjo was again in his element on Friday when news broke that he had done one of the things he is best known for in Nigeria’s political space: descending heavily on the man who served as his vice president for two terms spanning eight years, Alhaji Atiku Abubakar. In his latest onslaught, Obasanjo described his decision to pick Atiku as his deputy as his biggest mistake.

For many Nigerians who have followed the relationship between the two men over the years, the latest criticism came as no surprise. Rather, it appeared to be another chapter in a political feud that has refused to go away.

Nigeria has witnessed many political rivalries, but few have endured as long—or generated as much public interest—as the strained relationship between Obasanjo and Atiku. More than two decades after they jointly occupied the nation’s two highest offices, the wounds of that broken partnership appear far from healed.

The two men were indeed political partners who jointly won the presidential elections of 1999 and 2003. Their administration is widely believed to have played a significant role in stabilising Nigeria’s return to civilian rule after years of military dictatorship. Their relationship was initially cordial, with both men appearing united in pursuing the business of governance. However, that cordiality gradually gave way to mistrust, political disagreements and open confrontation. As events later unfolded, one of Nigeria’s strongest political partnerships became one of its deepest and most enduring rivalries.