The Hieronymites or Jeronimites, also formally known as the Order of Saint Jerome (Ordo Sancti Hieronymi; abbreviated OSH), is a Catholic cloistered religious order and a common name for several congregations of hermit monks living according to the Rule of Saint Augustine, though the role principle of their lives is that of the 5th-century hermit and biblical scholar Jerome.
The principal group with this name was founded in the Iberian Peninsula around the 14th century. Their religious habit is a white tunic with a brown, hooded scapular and a brown mantle. For liturgical services, they wear a brown cowl.
Established near Toledo, Spain, the order developed from a spontaneous interest of a number of eremitical communities in both Spain and Portugal imitating the life of Jerome and Paula of Rome. This way of life soon became widespread in Spain. Two of these hermits, Pedro Fernández y Pecha and Fernando Yáñez y de Figueroa, decided it would be more advantageous to live a more regular way of life in a community, under an authorized monastic rule.
Under their leadership, the Monastery of Saint Bartholomew was then founded in Lupiana, with Fernández y Pecha acting as the first prior. On 18 October 1373, Pope Gregory XI issued a papal bull recognizing them as a religious order, under the Rule of Saint Augustine. The constitutions included the teachings of their patron saint. By 1415 there numbered 25 houses following this spirit; in that year, they were united by the Pope and given the status of an exempt order, free from episcopal jurisdiction.
From its outset, the order enjoyed great favor from the king of Spain, and soon possessed some of the most famous monasteries in the Iberian Peninsula: including the Royal Monastery of Saint Mary of Guadalupe in Extremadura, Spain; the Royal Monastery of Saint Mary of Bethlehem in Lisbon, Portugal; and the magnificent monastery built by Philip II of Spain at El Escorial, where the kings of Spain were buried.