[2]: 362 While Ishaq was victorious, the army had lost significant manpower and leadership as the new Askia purged dozens of rebellious leaders from the western provinces.
A royal slave imprisoned at the remote but very valuable Taghaza salt mine escaped to Marrakesh, where he told the Sultan Ahmad I al-Mansur Saadi about the fractured and weakened Songhai.
Al-Mansur dispatched a letter in December 1589 demanding the revenue from Taghaza; Ishaq responded with bluster, but it failed to dissuade the Moroccans from sending a powerful force of musketeers to invade the Songhai empire.
Though Ishaq assembled more than 40,000 soldiers to meet the Moroccans, his army fled the enemy's gunpowder weapons at the decisive Battle of Tondibi in March 1591.
[2]: 365 Pasha Maḥmūd defeated the Songhai again at the battle of Zanzan on October 14, forcing Ishaq to flee to Dendi, where he was soon deposed and sent into exile in Gurma.