Henry I, Count of Vianden

Henry I (c.1200–1252) was the hereditary Count of Vianden in the Holy Roman Empire, from 1210 and, through his wife, Marquis of Namur from 1229.

Henry was the son of Frederic III, Count of Vianden (de) (c. 1160 - 1210), and Mechthild (Mathilde) of Neuerburg (?

In 1216 Henry married Margaret, Marchioness of Namur, sometimes called "Sibilia" (c. 1194 - 17 July 1270), daughter of Peter II of Courtenay and Yolanda of Flanders.

Baldwin sold Namur in c. 1263 to his cousin Guy of Dampierre, count of Flanders and Henry IV was removed by military force but they made peace with family marriage.

1285) whose husband Anselm (Anseau) de Cayeux (the younger) worked for King Charles I of Naples.