Nassau-Hadamar is the name of two side lines of theOttonian main line of theHouse of Nassau. The older line of the counts of Nassau-Hadamar existed from 1303 to 1394; the younger line existed from 1607 to 1711 and received the hereditary title ofprince in 1652.
After the death ofHenry II the Rich of Nassau his sons,Walram II andOtto I shared the inheritance in 1255. The boundary between the two territories was formed approximately by theRiver Lahn. Walram took over the southern part of the realm (Walramic main line) and Otto, the northern part (Ottonian main line). The marriage between Otto and Agnes ofLeiningen gave the Ottonian main line suzerainty over the March of Hadamar.
Otto's death in 1290 led to repeated inheritance disputes among his sons. In 1303, they shared his estate, under the mediation ofJohn I of Limburg. The eldest sonHenry took over the sub-county ofNassau-Siegen with its estate in theSiegerland and theBarony of Westerwald, the second sonEmich/Emicho I inherited the sub-county of Nassau-Hadamar withDriedorf andEsterau, and the third son,John the sub-county ofNassau-Dillenburg with its estates aroundDillenburg,Herborn,Mengerskirchen, theCalenberg Tithe and the jurisdiction (Gericht) ofHeimau.
