in thirteen years: William IX, Count of Poitiers (1153–1156) Henry the Young King (1155–1183) Matilda, Duchess of Saxony (1156–1189) – married Henry the Lion, Duke of Bavaria. The eldest amongst the couple's children, Richenza, is probably the daughter English chroniclers call Matilda, who was left in Normandy with her grandparents in 1185 and married firstly to Geoffrey, count of Perche, and secondly to Enguerrand de Coucy. The eldest son, Henry, became duke of Saxony and count palatine of the Rhine. His brother Otto was nominated by his uncle Richard I as earl of York and count of Poitiers before being elected emperor in opposition to the Hohenstaufen candidate. Otto was crowned in Rome but he was later excommunicated and declared deposed. Childless, Otto lost power following the defeat of the Welf and Angevin forces at the Battle of Bouvines. The youngest child, William of Winchester married Helena daughter of Valdemar I of Denmark. Their only son, also called Otto, was the sole male heir of his uncle Henry. The ducal house of Brunswick-Lüneburg and the British royal house of Windsor both descend from him. Richard I, King of England (1157–1199). He had no legitimate offspring, but is thought to have had two illegitimate sons, of whom little is known, called Fulk and Phillip, Lord of Cognac. Geoffrey II, Duke of Brittany (1158–1186) – married Constance daughter of Duke Conan of Brittany and became duke of Brittany by right of his wife. The couple's son Arthur I, Duke of Brittany was a competitor to John for the Angevin succession, who disappeared mysteriously as an adolescent in 1203. Eleanor, Queen of Castile (1161–1214) – married King Alfonso VIII of Castile. The couple's children included King Henry of Castile and four queen consorts, Berengaria, Queen of Leon, Urraca, Queen of Portugal, Blanche, Queen of France and Eleanor, Queen of Aragon. Joan, Queen of Sicily (1165–1199) – married firstly King William II of Sicily and secondly Count Raymond VI of Toulouse. Her children included Raymond VII of Toulouse. John, King of England (1166–1216) Henry also had illegitimate children with several mistresses, possibly as many as twelve. These children included Geoffrey, William, Peter and four children who died young by Alys, the daughter of Louis VII, while she was betrothed to his son Richard. William's many competencies and importance as a royal bastard led to a long and illustrious career. Henry reasserted and extended previous