German prince (1769–1843); field marshal in Russia
Source (Wikipedia): Peter Wittgenstein

Louis Adolf Peter, 1st Prince of Sayn-Wittgenstein-Ludwigsburg-Berleburg, better known as Peter Wittgenstein in English, was a prince of the German dynasty of Sayn-Wittgenstein and field marshal in the Imperial Russian Army during the Napoleonic Wars. He was nicknamed the Saviour of Saint-Petersburg.