Nassau-Siegen
Nassau-Siegen was an Ottonian Nassau county in the Siegerland on the upper Sieg. Count Henry I received Siegen in the 1303 partition and inherited Dillenburg in 1328; he still ruled in 1337.
Siegen passed fully from shared Nassau-Cologne rule to Nassau in 1381. Nassau-Siegen re-emerged in 1606, and John VII founded a Calvinist knightly academy in 1616. Divided into Catholic and Protestant halves from 1626, it was reunited under Orange in 1743. Napoleon gave Siegerland to Berg in 1806; Prussia received it in 1815.