A traditional rivalry between Brittany and Normandy continued at the close of the 11th century. The Breton-Norman war of 1064–1065 was the result of William the Bastard, Duke of Normandy (later to become known as William the Conqueror) support of rebels in Brittany against Alan's maternal uncle, Conan II.
Conan II died in late 1066 during a campaign in Anjou, and was succeeded by Alan's parents, Conan's sister, Hawise, and her husband, Hoel II. Alan became Duke in 1072, but being a minor, Hoel ruled as regent from Hawise's death in 1072 until Alan reached his majority in 1084.[a]
To prevent further hostilities during his invasion of England, William I married his daughter Constance to the new duke Alan in 1087.[4] The marriage ceremonies may have taken place in Bayeux in Normandy. William of Malmesbury wrote that Constance was unpopular at the Breton court because of her "severe and conservative" manner. However, Orderic Vitalis wrote that as duchess Constance did all she could to further the welfare of the Bretons, who grieved deeply at her death in 1090.
Alan IV died in 1119 at the monastery of Redon, where he had retired after his abdication in 1112, and separation from his wife Ermengarde. His only surviving son, Conan III succeeded him.
Bailey, B. Gregory; Bernard, Meaghan E.; Carrier, Gregory; Elliott, Cherise L.; Langdon, John; Leishman, Natalie; Mlynarz, Michal; Mykhed, Oksana; Sidders, Lindsay C. (2008). "Coming of Age and the Family in Medieval England". Journal of Family History. 33 (1). SAGE: 41–60. doi:10.1177/03631990073084492008.
Everard, J. A. (2004). Brittany and the Angevins: Province and Empire 1158–1203. Cambridge University Press.
Panton, James (2011). Historical Dictionary of the British Monarchy. Scarecrow Press. ISBN0810874970.
Piette, Gwenno (2008). A Concise History of Brittany. University of Wales Press.
Warren, W. L. (1974). Henry II. University of California Press.