In 1590, Ahmad I made Judar a pasha and appointed him the head of an invasion force against the Songhai Empire of what is now Mali. In October of that year, Judar set out from Marrakesh with a force of 1,500 light cavalry and 2,500 arquebusiers and light infantry. He also carried eight English cannon in his supply train, and assembled eighty Christian bodyguards for his personal detail.
Meanwhile, Songhai ruler Askia Ishaq II assembled a force of more than 40,000 men and moved north against the Moroccans; the two armies met at Tondibi in March 1591. Despite their inferior numbers, the Moroccan gunpowder weapons easily carried the day, resulting in a rout of the Songhai troops. Judar sacked Gao and then moved on to the trading centers of Djenné and Timbuktu.
Despite Judar's gains, sporadic battles continued with the Songhai army, leading to his replacement several years after his victory. Judar was subsequently put to death in December 1606 on the orders of Mulay Abd Allah, son of Mullay al-Shaykh in the course of struggles over the Moroccan throne.