Sayn-Wittgenstein-Sayn was a county of Rhineland-Palatinate, Germany, comprising the lands of the region of Sayn. It was created as a partition of Sayn-Wittgenstein in 1607, although it was not until the next year that it obtained fully the Countship of Sayn. The succession was never clear, leading to the annexation of the county in 1623 by the Archbishop of Cologne. It was not until a treaty in 1648 (at the end of the Thirty Years' War) that it was decided the county would pass to the sisters Ernestine and Johanette of Sayn-Wittgenstein-Sayn, under the regency of their mother, Countess Louise Juliane von Erbach (1603–1670). They partitioned the county into Sayn-Wittgenstein-Sayn-Altenkirchen and Sayn-Wittgenstein-Hachenburg soon after.[1]
William III (ruled from 1607–1623), third son of Count Louis I; married Countess Anna Elizabeth of Sayn-Sayn (1572-1608), the niece and heiress of Henry IV, Count of Sayn-Sayn.
Count William III's sons from his second marriage with Countess Anna Ottilie of Nassau-Weilburg (1582-1635) became Counts of Sayn-Wittgenstein-Sayn. The branch became extinct in 1846 with the death of Count Gustaf zu Sayn-Wittgenstein-Sayn (1811-1846).
Ludwig Adolf Peter, 1st Prince of Sayn-Wittgenstein-Berleburg-Ludwigsburg (Prussia) 1834 (1769–1843)[2]
Ludwig Adolf Friedrich, succeeded to Prussian titles 1843, 1st Prince of Sayn-Wittgenstein-Sayn 1861–1866 (1799–1866)
Peter, succeeded to Prussian titles 1866 (1831–1887)
Friedrich, succeeded younger brother Ludwig as 3rd Prince 1876–1879, resigned in favor of younger brother Alexander, succeeded older brother in Prussian titles 1887 (1836–1909)
his descendants hold various Prussian and Russian titles
Ludwig, 2nd Prince 1866–1876 (1843–1876)
Alexander, 4th Prince 1879–1883, resigned in favor of his son (1847–1940)
Stanislaus, 5th Prince 1883–1958 (1872–1958)
Prince Gustav Alexander of Sayn-Wittgenstein-Sayn (1880–1953)
Ludwig Stanislaus, 6th Prince 1953–1962 (1915–1962)