Simon I de Montfort (c. 1025 – 25 September 1087) was a French nobleman. He was born in Montfort l'Amaury, in the Duchy of Normandy, and became its lord. He was the son of Amaury I de Montfort and Bertrade. At his death he was buried about 20 miles (32 km) away in Épernon, because it was the site of the fortress he was instrumental in constructing.
Simon I de Montfort
|Seigneur de Montfort|
|Predecessor||Amaury I de Montfort|
|Successor||Amaury II de Montfort|
Kingdom of France
|Died||25 September 1087(aged 61–62)|
|Buried||Épernon, Kingdom of France|
|Noble family||House of Montfort|
|Spouse(s)||Isabel de Broyes|
|Father||Amaury I de Montfort|
- Amaury II de Montfort (c. 1056 – 1089), lord of Montfort
- Isabel (Elizabeth) de Montfort (b. 1057), who married Raoul II de Tosny, a companion of William the Conqueror.
- Bertrade de Montfort (c. 1059 – 1117), became queen of France.
- Richard de Montfort (c. 1066 – 1092), lord of Montfort, slain in attack on abbey at Conches.
- Simon II de Montfort (c. 1068 – 1104), lord of Montfort
- Amaury III de Montfort (c. 1070 – 1137), lord of Montfort and Count of Évreux.
- Guillaume de Montfort (c. 1073–1101), bishop of Paris.
- Adeliza de Montfort (b. 1075)
- Abels, Richard Philip; Bachrach, Bernard S., eds. (2001). The Normans and Their Adversaries at War. Boydell Press.
- Blacker, Jean (1998). "Women, Power, and Violence in Orderic Vitalis's "Historia Ecclesiastica"". In Roberts, Anna (ed.). Violence Against Women in Medieval Texts. University Press of Florida.
- Châtelain, André (1983). Châteaux forts et féodalité en Ile de France, du XIème au XIIIème siècle (in French). Nonette.
- Green, Judith A. (2000). "Robert Curthose Reassessed". In Harper-Bill, Christopher (ed.). Anglo-Norman Studies: Proceedings of the Battle Conference. Vol. 22. The Boydell Press.
- Lippiatt, Gregory Edward Martin (2017). Simon V of Montfort and Baronial Government, 1195-1218. Oxford University Press.
- Power, Daniel (2004). The Norman Frontier in the Twelfth and Early Thirteenth Centuries. Cambridge University Press.