Sayn-Wittgenstein was created when Count Salentin of Sayn-Homburg, a member of the House of Sponheim, married the heiress Countess Adelaide of Wittgenstein in 1345.

The area of both former counties is known today as "Wittgenstein", and is part of the district Siegen-Wittgenstein in the state of North Rhine-Westphalia.

[1][2] Being a childless bachelor, the elder of whose two younger brothers, Georg (1873-1960), had married morganatically, while the younger, Wilhelm (1877-1958), was 49 and yet unmarried, August preserved the name and heritage of his branch of the House of Sayn by adopting Christian Heinrich Prinz zu Sayn-Wittgenstein-Berleburg (1908-1953).

[1][2] In November 1960, Christian Heinrich, being the divorced father of two daughters by his dynastic marriage to Beatrix Grafin von Bismarck-Schönhausen (1921-2006), married Dagmar Prinzessin zu Sayn-Wittgenstein-Hohenstein (1919-2002), elder daughter of his adopted father's younger brother, Georg, who died seven months before the wedding.

[1] As Georg's children by his morganatic wife, Marie Rühm, (created Baroness von Freusburg by the reigning Prince of Lippe in 1916) had been de-morganatized[citation needed] by the declaration of their uncle August on 11 February 1947[citation needed], her marriage to Christian Heinrich was deemed a dynastic match, ensuring that their son Bernhart would be born in compliance with the house laws of his adoptive ancestors, the Sayn-Wittgenstein-Hohensteins, as well as being a grandson of the last dynastic male of that family, Prince Georg.