The Battle of Wayna Daga was a large-scale battle between the Ethiopian forces assisted by Portuguese musketeers and the forces of the Adal Sultanate and the Ottoman Empire in the east of Lake Tana in Ethiopia on 21 February 1543. The available sources give different dates for the battle. Led by the Emperor Galawdewos, the combined army of Ethiopian and Portuguese troops defeated the Adal-Ottoman army led by Imam Ahmad ibn Ibrahim al-Ghazi. One tradition states that Ahmad was shot by a musketeer before being beheaded. Once the Imam's soldiers learned of his death, they fled the battlefield. Background At the Battle of Wofla (28 August 1542), Imam Ahmad had crushed the Portuguese expeditionary force, killing most of its men, capturing practically all of the firearms they had, and capturing and killing its leader, Cristóvão da Gama. The Imam enjoyed a decisive victory over his greatest foe; armies in the Horn of Africa melted away with the death of their leaders. He then reduced the number of the mercenary Ottoman arquebusiers to 200, and relying on his own forces retired to Emfraz near Lake Tana for the coming rainy season. Miguel de Castanhoso states that these arquebusiers left his service because they were upset that he beheaded da Gama, whom they wanted to present to the Ottoman emperor. However, Beckingham notes that a Hadhrami chronicle states that some of them threatened the Imam's life unless he gave them 10,000 ounces of gold, to which he "gave a very favorable reply". When the rest of the group learned of their success, they came to the Imam and made a similar demand; deciding that he had no further need of their services, he sent them home giving them 2,000 ounces of gold. However, de Gama had inspired a fierce loyalty in his surviving followers, all but 50 of whom had reassembled after their defeat around Queen Seble Wongel, and taken refuge at "The Mountain of the Jews", which Whiteway identifies as Amba Sel. Castanhoso, writing decades after the fact, states that after the Emperor Gelawdewos had joined the survivors, and seeing the number of men who flocked to the Emperor's standard, at Christmas "we went to the Preste, and begged him to help us avenge the death of Dom Christovão." Gelawdewos agreed to march against the Imam. The Portuguese firearms which had been stored at Debre Damo were produced. A message was