The Battle of Wayna Daga was a large-scale battle between the Ethiopian forces and the Portuguese Empire 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. Imam Ahmad was killed in the battle and his followers were utterly routed.

The Ethiopian Empire, also formerly known by the exonym Abyssinia, or simply known as Ethiopia, was a sovereign state that historically encompasses the geographical area of present-day Ethiopia and Eritrea from the establishment of the Solomonic dynasty by Yekuno Amlak approximately in 1270 until the 1974 coup d'etat by the Derg, which dethroned Emperor Haile Selassie. By 1896, the empire incorporated other regions such as Hararghe, Gurage and Wolayita, and saw its largest expansion with the federation of Eritrea in 1952. Throughout much of its existence, it was surrounded by hostile forces in the African Horn; however, it managed to develop and preserve a kingdom based on its ancient form of Christianity.