<P> An interesting side - effect of Ethiopian Christianity was the way it intersected with a belief that had long prevailed in Europe of the existence of a Christian kingdom in the far east, whose monarch was known as Prester John . Originally thought to have been in the Orient, eventually the search for Prester John's mythical kingdom focused on Africa and particularly, the Christian empire in Ethiopia . This was first noticed when Zara Yaqob sent delegates to the Council of Florence in order to establish ties with the papacy and Western Christianity . They were confused when they arrived and council prelates insisted on calling their monarch Prester John, trying to explain that nowhere in Zara Yaqob's list of regnal names did that title occur . However, the delegates' admonitions did little to stop Europeans from referring to the monarch as their mythical Christian king, Prester John . </P> <P> Towards the close of the 15th century the Portuguese missions into Ethiopia began . Among others engaged in this search was Pêro da Covilhã, who arrived in Ethiopia in 1490, and, believing that he had at length reached the far - famed kingdom, presented to the nəgusä nägäst of the country (Eskender at the time) a letter from his master the king of Portugal, addressed to Prester John . Covilhã would establish positive relations between the two states and go on to remain there for many years . In 1507, the Emperor sent an Armenian named Matthew to the king of Portugal to request his aid against the Muslims . In 1520, the Portuguese fleet, with Matthew on board, entered the Red Sea in compliance with this request, and an embassy from the fleet visited the Emperor, Lebna Dengel, and remained in Ethiopia for about six years . One of this embassy was Father Francisco Álvares, who wrote one of the earliest accounts of the country . </P> <P> Between 1528 and 1540, armies of Muslims, under the Imam Ahmad ibn Ibrihim al - Ghazi, entered Ethiopia from the low country to the south - east, and overran the Abyssinian Kingdom, obliging the Emperor to take refuge in the mountain fastnesses . In this remote location, the ruler again turned to the Portuguese . João Bermudes, a subordinate member of the mission of 1520, who had remained in the country after the departure of the embassy, was, according to his own statement (which is untrustworthy), ordained successor to the Abuna (archbishop), and sent to Lisbon . Bermudes certainly came to Europe, but with what credentials is not known . </P> <P> In response to Bermudes message, a Portuguese fleet under the command of Estêvão da Gama, was sent from India and arrived at Massawa in February 1541 . Here he received an ambassador from the Emperor beseeching him to send help against the Muslims, and in the July following a force of 400 musketeers, under the command of Cristóvão da Gama, younger brother of the admiral, marched into the interior, and being joined by native troops were at first successful against the enemy; but they were subsequently defeated at the Battle of Wofla (28 August 1542), and their commander captured and executed . On February 21, 1543, however, Al - Ghazi was shot and killed in the Battle of Wayna Daga and his forces were totally routed . After this, quarrels arose between the Emperor and Bermudes, who had returned to Ethiopia with Gama and now urged the emperor to publicly profess his obedience to Rome . This the Emperor refused to do, and at length Bermudes was obliged to make his way out of the country . </P>

Which european group forged an alliance with the ethiopian kingdom in the 1540s