The Parish Church of Saint-Jean-Baptiste (Saint John the Baptist) in Aiglun was created at the end of the 11th century by the Bishop and the Chapter of Digne. It established and maintained an important site, which served as a cemetry for the neighbouring communities. The funerary functions of the site were extended, which was still used as a cemetery when the inhabitants regrouped around the castle and the Castral Chapel, within the walls of Le Vieil Aiglun (Old Aiglun).
 
The Church of Saint-Jean lost its importance when the cemetery was incorporated into the village, near the Church of Sainte-Marie-Madeleine. For a long time, there were many processions to the Church of Saint-Jean particularly on the occasion of Saint John's Saint Day, before gradually falling into decline towards the end of the 19th century.

The church's original plan was a Latin cross. The nave, with five bays, was covered with a barrel vault on double slats. Two doors led to the north and south arms of a false transept. The most remarkable remains are those of the south wall. The chapel has been badly ruined over the years and has undergone numerous renovations which have reduced its size.

The vault of the apse was rebuilt at the end of the 17th century.
As part of the restructuring of the landscape, the church is a remarkable monument that bears witness to the economic and spiritual evolution of the region during the Middle Ages.