Conan II, Duke of Brittany

Conan was the eldest child and heir of Alan III, Duke of Brittany by his wife Bertha of Blois, and member of the House of Rennes.

The 1064–1065 war between Brittany and Normandy was sparked after Duke William supported Rivallon I of Dol's rebellion against Conan II.

In 1065, before his invasion of Anglo-Saxon England, William of Normandy sent word to the surrounding counties, including Brittany, warning them against attacking his lands, on the grounds that his mission bore the papal banner.

During Conan's 1066 campaign against Anjou, he took Pouancé and Segré, and arrived in Château-Gontier, where he was found dead after donning poisoned riding gloves.

[citation needed] He was succeeded by his sister Hawise and brother-in-law, Hoël II, whose marriage may have been a political move to consolidate and stabilize the east and west regions of the duchy following Conan's death.