His daughter, who was born when he was old, kept Luxembourg and the smaller Ardennes lordships, while descendants of his sister Alice, who were also counts of Flanders and Hainaut, added possession of Namur to their dominion.

His elder brother Albert died young, about 1127, leaving Henry as next in line, and he subsequently started being associated with the government of the county of Namur from 1131.

[3] In 1136 Henry was active in his father's conflict against Count Godfrey I of Louvain, which followed the death of Anselm, the abbot of Gembloux.

Henry of Namur was eventually granted the feudal lordship and advocacies by the Emperor Lothair II, who thus prevented its passing to the French count of Grandpré.

[4] From the 10th to 12th centuries, the counts of Namur had lost power due to the expansionary policy of the neighbouring prince-bishops of Liège, and the uncertainty of comital rights versus those of the emperor.

The marriage of Henry's parents, whereby his father acquired the succession rights to the county of Luxembourg, has been described as a completion of this family project.

[5] Under Henry's lordship, Luxembourg was joined by several smaller Ardennes possessions which the family had acquired earlier.

Left without child, he designated his brother-in-law Count Baldwin IV of Hainault, husband of his sister Alice of Namur, as his heir.

[8] This birth called into question the plan of succession, as Henry considered his promise to Baldwin null and void.