The abbots of Affligem Abbey, which had been the ecclesiastical owners of the parish since the bishop of Cambrai ceded it to them in 1105, decided to build a priory for women in Forest, which would eventually become Forest Abbey. The first prioress was named in 1239. Also in the 13th century, the Romanesque church of Saint Denis was rebuilt in the newer Gothic style. The neighbouring abbey church was rebuilt in the 15th century. Relics of Saint Alena, whose cult was popular in the region, were formerly kept both in the parish church and in the abbey church, but since 1796 only in the parish church. Much of the abbey was destroyed by fire on 26 March 1764. The abbey was suppressed on 8 October 1796 and sold the following year. The buildings that survived the dismantling are now owned by the Brussels municipality of Forest, and are used as a cultural centre for seminars, banquets and exhibitions. The Abbey and the site were classified as a historical monument in 1994.
Abbesses
Petronella, daughter of Zeger, castellan of Ghent, installed 9 May 1239.
Aleyde de Goer, elected 6 December 1385, died 29 December 1385
Marie de Trazegnies, elected 27 November 1386, died 14 October 1388
Marie Sconinckx, elected 14 October 1388, died 6 September 1418
Catherine van Magdeghem, elected 7 September 1418, died 10 September 1430
Elizabeth Sconinckx, elected 19 February 1430, died 19 August 1457
Marguerite van Schoers, elected 20 July 1458, died 1489
Catherine van Bouchout, died at Utrecht on 6 October 1498
Barbe van Leaucourt, resigned, died at Anderlecht in 1516
Margareta van Liedekerke, transferred from the Abbey of Ghislenghien to reform Forest Abbey; arrived 24 July 1500; re-established discipline and good order, died 25 September 1541
Marguerite van Liedekerke, niece of previous, died 19 May 1560
Françoise de la Douve, died 3 April 1583, during disruptions of the Dutch Revolt: community lived as refugees in Dendermonde and Brussels from 1578; abbey burnt down by rebels in 1582
Adrienne du Petit-Cambrai, appointed by royal letters patent, installed 27 September 1587, rebuilt the monastery, died 6 November 1608
Maria de Taye, 25th abbess, installed 29 January 1609; died 29 July 1637
Françoise de Bette, 26th abbess, installed 25 July 1638; died 29 August 1666
Catherine Quarré, installed 12 September 1667; died 1 September 1668
