Name of inhabitants: Fresnois.
The earliest origins of Fresnay back to the 6th century where we note the presence of a dozen families on the site "Fraxinidum". It was not until the ninth century that the history of the city actually begins with the construction of the castle in 877 under the leadership of Charles the Bald. In fact the site seems ideal for the installation of a fortress as located on a rocky outcrop overlooking the Sarthe. Despite this, the city, known at the time as the Fresnay-le-Vicomte, undergo several assaults, those of William the Conqueror and later those of the English. With the attack of the English during the Hundred Years War, a native of the region will be honored: Ambroise de Lore, companion of Joan of Arc, named Captain of the city in recognition of his bravery.
Over the following centuries Fresnay be known for its hemp fabrics. This economy will mark the landscape of the city including the district of Bourg Neuf which lists many houses of weavers. The architecture of the houses is recognizable outside staircase leading to the first floor the only part of life, and at the bottom, slightly buried the weaving.
Fresnay-le-Vicomte become Fresnay-sur-Sarthe after the Revolution.