Omar Khayyám (born 1048 AD), was a Persian polymath, mathematician, philosopher, astronomer, physician, and poet. He also wrote treatises on mechanics, geography, and music.

He became established as one of the major mathematicians and astronomers of the medieval period. Recognized as the author of the most important treatise on algebra before modern times as reflected in his Treatise on Demonstration of Problems of Algebra giving a geometric method for solving cubic equations by intersecting a hyperbola with a circle. He also contributed to the calendar reform and may have proposed a heliocentric theory well before Copernicus.

Saint John of the Cross (San Juan de la Cruz) (24 June 1542 — 14 December 1591), born Juan de Yepes Alvarez, was a major figure of the Catholic Reformation, a Spanish mystic, and Carmelite friar and priest, born at Fontiveros, Old Castile.

Saint John of the Cross was a reformer of the Carmelite Order and is considered, along with Saint Teresa of Ávila, as a founder of the Discalced Carmelites. He is also known for his writings. Both his poetry and his studies on the growth of the soul are considered the summit of mystical Spanish literature and one of the peaks of all Spanish literature. He was canonized as a saint in 1726 by Pope Benedict XIII.