HENRY I. (Ioo8-1o6o), king of France, son of King Robert and his queen, Constance of Aquitaine, and grandson of Hugh Capet, succeeded his father in Io31, although in 1027 he had already been anointed king at Reims and associated in the govern ment with his father. His mother formed a powerful league with her younger son Robert, against him, and he was forced to take refuge with Robert II., duke of Normandy. In the civil war which resulted, Henry finally defeated his opponents in 1032. Constance died in 1034, and Robert was given the duchy of Burgundy, thus founding that great collateral line which was to rival the kings of France for three centuries. From 1033 to Io43 Henry was in volved in a life and death contest with those nobles whose territory adjoined the royal domains, especially with the house of Blois and the counts of Champagne. Henry's success was largely due to the help given him by Robert of Normandy, but upon the acces sion of Robert's son William (the Conqueror), Normandy itself became the chief danger. From Io47 until his death, Henry was almost constantly at war with William, who held his own against two royal invasions, in 1055 and Io58. Henry's reign marks the height of feudalism, Normandy, Champagne and Burgundy being only nominally subject to royal authority. Yet Henry maintained the independence of the clergy against the pope Leo IX., and claimed Lorraine from the emperor Henry III. In 10S9 he had his eldest son Philip crowned as joint king, and died the following year. Henry married in Io43 Maud, niece of the emperor Henry III., who died childless in 1044. In 1051 Henry married the Rus sian princess Anne, daughter of Yaroslav I., grand duke of Kiev. She bore him two sons, Philip, his successor, and Hugh, count of Vermandois.
See the Historiae of Rudolph Glaber, edited by M. Prou (Paris, 1886) ; F. Sochnee, Catalogue des actes d'Henri ter (19o7) ; de Caiz de Saint Aymour, Anne de Russie, reine de France (1896) ; E. Lavisse, Histoire de France, tome ii. (1901) , and the article on Henry I. in La Grande Encyclopedic by M. Prou.