Henry IV, called the Blind (l'Aveugle or der Blinde), was count of Luxembourg from 1136 until his death and count of Namur (as Henry I) from 1139 until his abdication in 1189. He was the son of Godfrey I, Count of Namur and Ermesinde, a daughter of Conrad I of Luxembourg.
He inherited the counties of La Roche and Durbuy from his cousins Henry II of Durbuy and Henry of Laroche. When another cousin, Conrad II of Luxembourg, died he was granted that county by the Emperor Lothair II, who thus prevented its passing to the French count of Grandpré. At the same time he also inherited the advocacies of the abbeys of Saint-Maximin at Trier and Saint-Willibrord at Echternach. This was the cause of many conflicts with Albero of Montreuil, archbishop of Trier. Three years later, he inherited Namur from his father.
In 1171, Henry married a second time, this time to Agnes, daughter of Henry I, Count of Guelders and Agnes of Arnstein. Heirless still, he repudiated her in 1184, but fell seriously ill and rejoined her. In September 1186, a girl, Ermesinde, was born to them. This birth called into question the plan of succession, as Henry considered his promise to Baldwin null and void. Henry, then 76 years old, pledged his daughter in marriage to Henry II of Champagne. Baldwin still claimed his inheritance. It was then decided that Baldwin would inherit Namur, Ermesinde would inherit Durbuy and La Roche, and Luxembourg (fief masculin) would revert to the Empire.
The fiefs were dispensed in 1189. After the planned marriage between Ermesinde and the count of Champagne was cancelled, Henry bethrothed her instead to Theobald I of Bar. He entered into a war with Henry of Limburg and was defeated on 1 August 1194 at Noville-sur-Mehaigne. He died two years later in Echternach.