The origin of the Order in Spain remains shrouded in mist, though the researches of such scholars as Frs. Otger Steggink, Pablo Garrido and Balbino Velasco Bayon, have done much to clarify the problem.

According to a 16th century English Carmelite, the General Chapter of London in 1254 decreed the founding of houses of the Order in Spain. In fact a number of houses are known to have been in existence not long after that date. The impetus for this movement came from the Southern French Provinces of Province and Aquitaine, part of which lay under the crown of Aragon.

A Province of Spain is listed in the General Chapter of 1281. In 1354 Catalonia was separated from the Province of Spain, and in 1416 the latter was divided into Aragon and Castile. The Carmelite Order in Spain received its definitive form in 1498 when Andalusia was separated from Castile. Aragon took precedence over the others as the most ancient. In the 18th century it reached its maximum development with 24 convents and 745 members.

After the suppression of 1835 the Aragonese convents of Onda and Caudete with Jerez de la Frontera in Andalusia revived the Province of Spain in 1890. By 1906 Aragon, under the title Arago-Valentine, was again a Province with 50 members. The Province suffered a set-back in the Civil War (1936-1939), when 28 of its members were killed, but it has since grown and expanded across the seas to Puerto Rico and the Dominican Republic.

This Province is honoured by the fact that it is the Province of two great saints of the Church: Teresa of Jesus and John of the Cross. It was founded in 1416, when the Province of Spain was split into the two Provinces of Aragon and Castile. It was this Province which preserved the title and location of the ancient Province of Spain up to 1469. It included the convents of Toledo, Requena, Avila, Salamanca, San Pablo de la Moraleja, Santa Maria de los Valles, Gibraleon, Seville and Escacena, and, a little later, Ecija. In 1498 the four last mentioned houses were separated from Castile to form the new Province of Andalusia (Betica). The same thing had happened previously in 1425 when the convents of Moura and Lisbon, which belonged to Castile, gave rise to the Province of Portugal.

The Province remained relatively small, a situation which led St. Teresa to say that it was about to disappear. But later events have shown that the fear of St. Teresa was not well-founded, for in the years 1550-1557, the Prior General, Nicholas Audet, had included the Province among those which had accepted completely his reform, and which consequently grew in number of convents and religious, and, during the closing decades of the XVIIth century and through the following century, enjoyed its period of grand splendour. In the schools of the Province, which were affiliated to the Universities of Toledo, Salamanca, Alcala de Henares and Valladolid, many religious flourished in wisdom and virtue. Among these we recall especially the great mystic, Miguel de la Fuente and the great theologians, Pedro Cornejo de Pedrosa, Juan Bautista de Lezana and Luis Pérez de Castro. This Province, which through the centuries has given to the Order two Priors General, Juan González Feijoo de Villalobos (1692-1698) and Manuel Regidor y Brihuega (1825-1831), and fourteen bishops to the Church, also included the monasteries of nuns in Avila, Fontiveros and Piedrahita, founded at the end of the XVth and the beginning of the XVIth centuries. There were also two more monasteries of nuns founded in the XVIIth century in Madrid.

As was the case with all religious in Spain, the Province of Castile was suppressed by the government in 1835. The restoration of the Province began in 1948, when the Commissariat of Castile was established with houses in El Henar, Salamanca and Lomas de Zamora (Argentina). To these were added the houses in Madrid and Valladolid. The monasteries of nuns in Madrid (Maravillas), Piedrahita and Fontiveros, which managed to survive the decree of exclaustration, also belonged to the Commissariat. In 1984, Castile regained its status as a Province.