Otto I, Count of Nassau

Otto I of Nassau ( † 1289/1290 ) was the founder of the Ottonian line of the House of Nassau.

Otto was the third son of Count Henry II of Nassau and of the kingdoms of Matilda of Geldern. After Henry II was 1250/51 died, it came between Otto and his brother Walram, the founder of walramischen line of the House of Nassau, to a long-standing dispute over the inheritance. This was settled on December 17, 1255 with a sharing agreement. After Otto received the northern part of the country with wins, Dillenburg, Herborn and Haiger, while the country south of the Lahn with Weilburg and Idstein went to Walram. With other princes came to the battle, so especially with the Archbishops of Trier and Cologne, during which Otto lost the bailiwicks about Ems and Koblenz. In addition, Otto has been banned because he refused the Teutonic Knights surrendered lands, the claimed this for themselves. Even with the Lords of Greifenstein Dernbach and he was involved in violent feuds.

Otto was married to Elisabeth of Leiningen- Landeck ( † about 1303), daughter of Count Emich IV of Leiningen- Landeck. With her he had the following children:

• Henry III. , Count of Nassau- Siegen ( † 1343 )
• Johann, Count of Nassau- Dillenburg († August 10, 1328 )
• Emich, Count of Nassau- Hadamar († June 7, 1334 ), ∞ before 1297 Anne of Nuremberg
• Gertrude, 1329-1359 Abbess of Altenburg ( † September 19, 1359 )
• Otto, a canon of Worms († September 3, 1302 )
• Mechtild ( † before October 29, 1319 ), ∞ Count Gerhard I of Vianden ( † 1317 )