The first reliable news of the cultivation of the vine in the current province of Madrid, are related to the Monastery of San Martín de Valdeiglesias, whose ruins remain in the municipality of Pelayos de la Presa, 62 kilometers from Madrid and 5 from San Martín of Valdeiglesias.
The origin of the Monastery of San Martín de Valdeiglesias in the 12th century was the then existence of twelve hermitages or churches then separated from each other, from where the parish church of the town of San Martín is to the Alberche river, occupying a wide valley, for then called “Valle de Yglesias”, which gave its name to the Monastery run by the Order of San Benito and later to the town of San Martín de Valdeiglesias.
King Alfonso VII, aware of the sanctity of the hermits, granted in 1148 the extension of the inheritance over land and surrounding goods in perpetuity, sending monks from La Espina to Valdeiglesias, in order for the residents there to take the Cistercian habit. And Fernando III “El Santo” once again expanded the community’s domains with the Santa Cruz de Alarza Farm “As the monks had destined all their possessions in the valley to the cultivation of the vine, and they lacked land for other crops necessary for the survival of it ”. The assignment was later ratified by Kings Alfonso X and Sancho IV.
The monks were the colonizers of the valley and those who founded the town of San Martín, so that the settlers and other servants of the Monastery lived there, “creating a great wine wealth”. They learned the science of wine from its founders, the brothers of the Order from La Espina, who already mastered it in their place of origin.
Referring to King Fernando III “The Saint”, Father Manrique in his Cistercian Annals says: “Among other things, the wealth of the place and the House increased, and the fertility of the land, very suitable for planting vines, of which They obtain generous wines, commonly called San Martín and they are the most fruitful in all of Europe, even if I said that they occupy the first place of all, I would not be wrong ”.

Referencia: TRATADO DE VITICULTURA GENERAL
LUIS HIDALGO