The origins of the founding of the Church-Monastery of Vera Cruz de Marmelar are quite remote, since the current temple was built on previous foundations.
The parish of Vera Cruz, previously called Marmelar or at least known as the place of S. Pedro de Marmelar in documents from the 13th century, is a very old and historic town, and this Monument has accompanied its steps over the centuries.
According to various studies, a previous Visigothic or Mozarabic temple existed before this construction, of which there are still remains. In 1240, the knights of the Order of the Hospitallers founded the village and promoted the conversion of the Christian building into a monastery.
The structure of the temple that has survived to this day generally dates from the Gothic period, although it underwent later works, particularly in the 17th century.
The Church of Vera Cruz de Marmelar also went down in history for holding an important relic: a part of the cross on which Jesus Christ was allegedly crucified, the famous relic of the Holy Wood, probably collected in the Battle of Salado, thus making Marmelar one of the four temples in the kingdom where the memory of this glorious battle was evoked (Évora Cathedral, Lisbon Cathedral and Santiago do Cacém Parish Church).