Sebastián de Benalcázar
One of Francisco Pizarro's captains, who took Quito in 1534, heard there of the gilded ruler, and later reached the Muisca highlands from the south.
The Gilded Chief of Lake Guatavita
Juan Rodríguez Freyle, Conquest and Discovery of the New Kingdom of Granada (El Carnero), 1636, chapter 2: the ceremony at Guatavita · written in 1636 (describes a Muisca rite of before 1537, as told to the writer decades later)
De esta ceremonia se tomó aquel nombre tan celebrado del Dorado, que tantas vidas ha costado i haciendas. En el Perú fué donde sonó primero este nombre dorado; i fué el caso que habiendo ganado a Quito, donde Sebastian de Benalcázar, i andando en aquellas guerras o conquistas, topó con un indio de este Reino de los de Bogotá, el cual le dijo, que cuando querian en su tierra hacer su rei, lo llevaban a una laguna mui grande, i allí lo doraban todo, o le cubrian de oro, i con muchas fiestas lo hacian rei. De aquí vino a decir el Don Sebastian “vamos a buscar este indio dorado.” De aquí corrió la voz a Castilla i a las demas partes de Indias, i a Benalcázar le movió venirlo a buscar, como vino, i se halló en esta conquista i fundacion de esta ciudad, como mas largo lo cuenta el padre frai Pedro Simon en la quinta parte de sus noticias historiales, donde se podrá ver.
From this ceremony came that famous name, El Dorado, the Gilded One, which has cost so many lives and fortunes. It was in Peru that the name was first heard. After Quito had been won, Sebastián de Benalcázar, who was fighting in those wars and conquests, came upon an Indian from this kingdom, one of the people of Bogotá. The Indian told him how they made a king in his land. They took him to a very large lake and gilded him all over, or covered him with gold. Then they made him king with great festivities. That is why Don Sebastián said, “Let us go and look for this gilded Indian.” From there the word spread to Castile and the rest of the Indies. It moved Benalcázar to come looking for him, and so he did, and he took part in the conquest of this kingdom and the founding of this city. Father Fray Pedro Simón tells this at greater length in the fifth part of his Historical Notices, where it can be read.