Ida, Countess of Hainaut (Ida of Louvain) (died 1139), daughter of Henry II, Count of Louvain, and Adela of Thuringa. Ida was sister to Godfrey I, Count of Louvain, and grand-niece to both Pope Stephen IX and Godfrey the Bearded, Duke of Lorraine. She is sometimes confused with Ida of Louvain, a 13th-century nun. Ida was married to Baldwin II, Count of Hainaut, who served in the First Crusade with Godfrey of Bouillon. Ida and Baldwin had nine children: While on a pilgrimage to Jerusalem in 1106, Ida organized a search for her lost husband in Anatolia but to no avail. Ida’s fate remains unknown.