The Lys River, a tributary of the Layon, flows along the West side of Montilliers.
The famous, Foulques Nerra built a church on the “mount” (highest point in the area) and called it
“Mons écclésiacus” wich means “mount of the church” or “mount of the monks”.

The Priory was built, next to the church, by monks from the abbey of Saint Florent in Saumur who settled in 1026 in Montilliers.
Sgrebran de Passavant had obtained permission from Foulques Nerra.
The Priory was sold as part of the nation’s belongings to an innkeeper of Vihiers after the Revolution in 1791.
In 1808, the old Priory was turned into a geriatric hospital. In 1997, the retirement home was rehabilitated.

The church, next to the prieuré, was repaired and enlarged in 1849 after having been burned down during the Guerres de Vendée. 
Only the choir loft and framework remain from the 11th century.  

Architects from Nantes built the current church of Montilliers, dedicated to Saint Hilaire, from 1904 to 1908. Three stained glass windows of the church are listed as historic monuments :
- The stained glass of the Mill of the Queen was fitted in 1909.
It recalls the shooting of 22 women and children by the republicans, on 5th April 1794.
- The stained glass of the visit of Bertrand de Got, who later
became Pope Clément V,  to Montilliers was fitted in 1928.
- The stained glass of Father Raison was fitted in 1929.
It represents the return of Father Raison to Montilliers after having spent nine years of deportation to Spain, from 1792 to 1801, for refusing to take oath in 1790.

The  ancient washhouse is located at the spot of La Fontaine
and was restaured in 1998.

Marie Leroy  was shot on 1st February 1794 on the  of “field of the Martyrs” in Avrillé and beatified on 19th February 1984.