It is known, from different archaeological finds, that the municipality of Orcajo could have been inhabited since the Neolithic period but, although vestiges prior to the thirteenth century have also been found, although vestiges prior to the thirteenth century have also been found, it will be in the year 1205 when It appears cited as a village in the Bermejo Book of the Santa María de Daroca Collegiate Archive.
In 1248, by the privilege of Jaime I, he separated from the dependency of Daroca, becoming part of the Sesma de Gallocanta, in the Community of Aldeas de Daroca, although his church would continue to pay tithes to the collegiate church of Santa María darocense until the 15th century. .
The so-called War of the Two Pedros (1356-1369), between the kings of Aragon and Castile, will be devastating for the border territories, at which time it is likely that the tower of the Orcajo church served as a watchtower and defensive watchtower. It will not be the only cross-border warlike moment: In 1453 Prince Enrique of Castile, with two hundred and fifty horsemen, in a fast ride, returned to tour and loot the villages of the Community, among them Orcajo.
As a town near Balconchán, a place crossed by the old Camino Real from Madrid to Barcelona (prior to National II), the mountains of Orcajo were rest and repose for the Carlist troops in their Royal March towards Madrid, after the Battle of Villar de los Navarros (August 24, 1837).
Already in the twentieth century, the municipality, like the Daroca region, gradually separated from the main road network, with a purely agricultural and livestock economy faced with developmentalism after the Civil War, will lose most of its population. But in this XXI century the memory of those who inhabited it, the affection that the grandparents instilled in the new generations and a new rediscovery of the rural world and its values, are causing some to reopen the houses of Orcajo.
One of these "values" is found among the mountains of the Orcajino municipality: At the beginning of the 20th century, an enormous campaign of reforestation of the mountains adjacent to the Jiloca Valley was carried out. Among the different tree varieties chosen, the engineer in charge decided to put a consignment of Abies pinsapo in Orcajo, a fir endemic to the south of the Iberian Peninsula and North Africa. More than a century has passed and, what was a small forest area, has become naturalized and today it occupies about 15 hectares. The Pinsapar de Orcajo is the protagonist of a story of success and adaptation to climatological and environmental conditions different from its natural habitat and was cataloged in 2018 as Singular Grove of Aragón.
Acered - Aldehuela de Liestos - Anento - Atea - Badules - Balconchán - Berrueco - Cerveruela - Cubel - Cuerlas (Las) - Daroca - Fombuena - Gallocanta - Herrera de los Navarros - Langa del Castillo - Lechón - Luesma - Mainar - Manchones - Murero - Nombrevilla - Orcajo - Retascón - Romanos - Santed - Torralba de los Frailes - Torralbilla - Used - Val de San Martín - Valdehorna - Villadoz - Villanueva de Jiloca - Villar de los Navarros - Villarreal de Huerva - Villarroya del Campo