merged with Nassau-Weilburg to form the Duchy of Nassau. See "Dukes of Nassau" above. Following Frederick Augustus' death, the princely title was adopted (in pretense) by his half brother through an unequal marriage, Karl Philip. As head of the House in 1907, Wilhelm IV declared the Count of Merenberg non-dynastic; by extension, this would indicate that (according to Luxembourgish laws regarding the House of Nassau) this branch would assume the Salic headship of the house in 1965, following the death of the last male Count of Merenberg. The Ottonian Line The partition of the county of Nassau between Otto, and his older brother Walram (above), resulted in a permanent division between the 2 branches of the family. The Walramian branch tended to concentrate on their German lands, while the Ottonians, as we will see below, established themselves in the Netherlands and became great magnates, leaders of the Dutch Revolt, the stadtholders of the Dutch Republican government, and eventual kings of the Netherlands. This, however, was not before many divisions and reunitings. The first was between sons of Otto, with the main power base being centered around the caste of Dillenburg: 1255–1290: Otto I, Count of Nassau in Siegen, Dillenburg, Beilstein, and Ginsberg 1290–1303: Joint rule by Henry, John and Emicho I, sons of Otto I In 1303, Otto's sons divided the possessions of the Ottonian line. Henry received Nassau-Siegen, John received Nassau-Dillenburg and Emicho I received Nassau-Hadamar. After John's death. Nassau-Dillenburg fell to Henry. Counts of Nassau-Dillenburg The Ottonian portion of the county of Nassau was divided and sub-divided, as shown in the genealogical charts below, several times, so that each son of the previous count would have a portion. Eventually, these lines would all die out in favor of the main branch of the family, which had established themselves in The Netherlands. Counts of Nassau-Beilstein The counts of Nassau in Beilstein were involved mostly in local/regional German affairs in their area of the Rhine. In 1343, Nassau-Beilstein was split off from Nassau-Dillenburg. After John III's death, Nassau-Beilstein fell back to Nassau-Dillenburg. It was split off again in 1607 (see below) for George, who inherited the rest of Nassau-Dillenburg in 1620. First Counts and Princes of Nassau-Hadamar First House of Nassau-Siegen The branch of Nassau-Siegen was a collateral line of the House of Nassau, and ruled in Siegen. The first Count of Nassau-Siegen was Henry I, Count of Nassau-Siegen (d.