ONDEGARDO, Polo (on-day-gar'-do), Spanish historian, born in Spain about 1500 ; died in Peru about 1570. The exact date of his arrival in Peru is unknown. According to William H. Prescott, when Governor Pedro de la Oasca (q. r.) arrived to suppress the usurpation of Gonzalo Pizarro, Ondegardo was one of the judges of the audiencia, which had submitted to the usurper, but he always counselled moderation, and when the extreme party gained the ascendant, Ondegardo joined the army of Gasca and accompanied him till the battle of Saesahuana, 9 April, 1548. Gasca appointed him governor of Charcas, and under the Marquis de Canete he became governor of Cuzco, whence, by the viceroy's order, he removed the mummies of the incas to lama. He was a student of Peruvian antiquities, and gaining the good-will of the Indians, he was able to study their history, religion, and customs, of which he wrote two interesting accounts--the first to the Marquis de Cafiete in 1561 ; the second was furnished ten years later: but neither was printed, the manuscript remaining in the archives of Simancas and the Escorial. Prescott copied them from the collection of Lord Kingsborough, and used them for his "History of the Conquest of Peru." During the rebellion of Francisco Hernandez Giron, Ondegardo accompanied Alvarado as commander of infantry in the battle of Chnquinga in 1554, where Alvarado was totally defeated, his name does not appear again till the government of Francisco de Toledo, when he is mentioned as one of the men of science consulted by that viceroy.