[1] Ludwig was half-Polish through his mother, Antonia Cäcilie Snarska (1778–1856), and was formally known in Russian as Lev Petrovich Vitgenshtein (Лев Петрович Витгенштейн).

[2] In 1821, he represented Russia at the coronation of King George IV of the United Kingdom, but his career came to a halt when his participation in the Decembrist societies was revealed in 1826.

She was a daughter of Prince Ivan Ivanovich Baryatinsky (son of Princess Catherine of Schleswig-Holstein-Sonderburg-Beck) and Countess Marie Wilhelmine von Keller (a daughter of Count Christoph von Keller and Ludwig's aunt, Countess Amalie Louise zu Sayn-Wittgenstein-Ludwigsburg).

[2] From his first marriage, he came into possession of the largest privately owned estate in Central Europe covering roughly 12,000 km2 (4,600 sq mi) of fields, forests, villages and towns in the former Polish–Lithuanian Commonwealth.

From 1861 forward, he himself, and then his descendants (only the eldest in male lines), were called the Most Serene Princes of Sayn-Wittgenstein-Sayn, making the children from his Russian wife German again.