Dudo-Henry of Laurenburg (German: Dudo-Heinrich von Laurenburg; Latin: Dudo-Henricus; c. 1060 – c. 1123) was Count of Laurenburg in 1093 and is considered the founder of the House of Nassau. The House of Nassau would become an important aristocratic family in Germany, from which are descended through females the present-day royals of the Netherlands and Luxembourg, while officially belonging to this House.
Count Dudo was the son of Robert (German: Ruprecht), the Archbishop of Mainz’s Vogt in Siegerland. It is presumed from their ancestral possessions in the Lipporn area that they were descendants of the Lords of Lipporn, who were mentioned as early as 881 in a document of Prüm Abbey as the owners of parts of the Lipporn-Laurenburg area. Around 950, the Lords of Lipporn obtained the Esterau (the area near present day Holzappel) from Herman I, Duke of Swabia. In 991, a Drutwin from Lipporn is mentioned as Count in the Königssondergau east of Wiesbaden.
Probably with his father, Dudo built the castle of Laurenburg on the edge of the Esterau. This was sometime before 1093, because a "Comes Dudo de Lurenburch" is mentioned in founding charter of the Maria Laach Abbey, in fifth place of the witness list. Some historians, however, have claimed that this document was fabricated. He is later mentioned in a document from 1117 as the Vogt in Siegerland, having succeeded his father. He was a supporter of the Salian emperors, opposing the Archbishops of Mainz, Cologne, and Trier and the Counts of Katzenelnbogen.
Around 1100, Dudo began building Nassau Castle, which would eventually become the home castle of the House of Nassau. This resulted in a century-long dispute with the Bishopric of Worms, which owned the land.
In 1117, Dudo donated land to Schaffhausen Abbey for construction of a monastery in Lipporn. This monastery, built under Dudo's son Robert I in 1126, was the Benedictine Schönau Abbey. From 1141 until her death in 1164, the abbey would be the home of St. Elizabeth of Schönau.
In 1122, Dudo received the castle of Idstein in the Taunus as a fief under the Archbishopric of Mainz. This was part of the inheritance of Count Udalrich of Idstein-Eppstein. He also received the Vogtship of the richly endowed Benedictine Bleidenstadt Abbey (in present-day Taunusstein).
Dudo-Henry of Laurenburg married Anastasia of Arnstein an der Lahn (near present-day Obernhof), daughter of Count Louis II of Arnstein (Anastasia, possibly as heiress to Louis II, had claims on the Vogtship of Koblenz). Three children were born of this union: