Alan IV, Duke of Brittany 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. Hoel ruled as regent from Hawise's death in 1072 until Alan reached his majority in 1084. To prevent further hostilities during his invasion of England, William I married his daughter Constance to the new duke Alan in 1087. The marriage ceremonies may have taken place in Bayeux in Normandy.
William, Duke of Brunswick William, Duke of Brunswick William, Duke of Brunswick (; 25 April 1806 – 18 October 1884), was ruling duke of the Duchy of Brunswick from 1830 until his death. William was the second son of Frederick William, Duke of Brunswick-Lüneburg, and after the death of his father in 1815, was under the guardianship of King George IV of the United Kingdom. He became a Prussian major in 1823. When his brother, Charles, was deposed as ruling duke by a rebellion in 1830, William took over the government provisionally. In 1831, a family law of the House of Guelph made William