Charles-Maurice de Talleyrand-Périgord
He was a bishop and worked successfully for Louis XVI. He changed sides and served the French Revolution and Napoleon I. When Napoleon started losing his wars, Talleyrand changed sides again and served  Louis XVIII. He represented France at the Congress of Vienna. He changed sides once more and served Louis Philippe I. Since the beginning of the 19th century he was known simply as Talleyrand. He is widely seen as one of the most pragmatic and influential diplomats in European history. He was known to accept bribes from other European powers, especially while he served under Napoleon.