Provides a guide to the Rothschild family papers that were discovered in 1990 in the collections of the former Central State Special Archive in Moscow. Prints the text of a letter dated 3 April 1848 from Klemens von Metternich to Salomon Rothschild thanking Rothschild for his letter of credit, which enabled Metternich to travel to his exile in England after the 1848 Revolution. The document was discovered in the massive files that constitute the Rothschild Collection.