The history of the commune of Forest begins in the early 12th century when Gilbertus, the son of Baldwin of Aalst, left on crusade after having asked Fulgence, the superior of the abbey at Af-flighem, to build a cloister for his mother and sister to reside in together with other pious women during the absence of the soldiers. The abbey was founded in 1105 in the valley of the Senne River at the foot of the forested slope of the Forêt de Soignes on land within the domain of the prince sovereign called Vorstbosch ("prince's wood"), later translated in a church document as Forestum.
Rustic dwellings built around the priory grew into a hamlet and the priory, inhabited by Benedictines, became independent of the abbey of Afflighem in 1245. The first right to self-government dates from 1213. A hospital, hostel, bakery, brickworks, and water mills were built. The abbey, destroyed by fire, was rebuilt in 1764-1765. The abbess acquired lordship over Forest from the duke of Brabant in 1238, and, until 1797 and the abolition of religious orders, she exercised extensive judicial and fiscal powers. Forest was included in the cuve of Brussels in 1394.
The area remained heavily wooded. Only 993 inhabitants are registered in 1831 and 6,099 in 1900. By 1910, the numbers had grown to 24,223 in the wake of development of the Saint-Augustin district under the impetus of financier Alexander Bertrand. In 1933, the avenue Victor Rousseau was laid out, which did much to promote growth.
A commune within the Brussels Capital Region, Forest retains considerable wooded space, including the Parc de Forest, laid out in the 1870s by order of King Leopold II, and the Parc Duden, a forested stretch bequeathed by German businessman Wilhelm Duden to King Leopold in 1895 and purchased by the town in 1911. The park opened in 1912.
Historical Dictionary of Brussels. Paul F. State.