Lope de Barrientos, Castilian bishop (b. 1389)
Lope de Barrientos (1382–1469), sometimes called Obispo Barrientos ("Bishop Barrientos"), was a powerful clergyman and statesman of the Crown of Castile during the 15th century, although his prominence and the influence he wielded during his lifetime is not a subject of common study in Spanish history.

From relatively humble beginnings in Medina del Campo, where he studied grammar, he took advantage of a secular custom of Castilian monarchs to selectively promote lower class court nobility to the service of Ferdinand I of Aragon—a privilege normally reserved for those of high birth.

Barrientos exploited every opening to climb in social rank against the backdrop of a complex political atmosphere: he became a Dominican friar; served as a professor of theology at the University of Salamanca (possibly the first); as the bishop of three successive cities—Segovia, Ávila, and chiefly of Cuenca

—as royal confessor of John II of Castile; an Inquisitor; an advisor to Henry IV of Castile; and as Chancellor of Castile. In addition, he published a series of theological treatises and tracts concerning religious problems encountered in 15th-century Spain.