Otto I of Nassau
…3 May 1289 and 19 March 1290) was Count of Nassau and is the ancestor of the Ottonian branch of the House of Nassau. Otto was the third son of Count Henry II of Nassau and Matilda of Guelders and Zutphen, the youngest daughter of Count Otto I of Guelders and Zutphen and Richardis of Bavaria (herself daughter of Otto…