The collection consists of correspondence, manuscripts by Messner and others, memoirs by Messner, photographs and printed materials. Manuscripts by Messner include a typescript (275 p.) entitled "Nekotorye prichiny porazhenii︠a︡ Germanii v voĭnu 1939-1945 g.g." Messner's memoirs (3293 p. and 350 p.) cover the years 1914-1973. Included among them are clippings, photographs, mimeographed materials and pamphlets. The majority of his memoirs concern World War I and the Civil War. Photographs are mostly copies. Printed materials consist mostly of clippings of articles by Messner in South American monarchist periodicals.

The collection includes copies of official communiques sent and received by the Russian Imperial Embassy in London for the period 1886-1890 and 1919-1922; copies of reports forwarded by E.V. Sablin to the Council of Ambassadors in Paris, for the period 1922-1937; correspondence grouped around specific subjects; "case files" containing letters from and on behalf of individual Russian emigres wishing to enter Great Britain or to adjust their immigrant status; and letters received by E.V. Sablin and his wife Nadezhda Ivanovna from various persons, together with carbon copies of their replies. The most voluminous correspondence is between E.V. Sablin and V.A. Maklakov, V. Dobuzhinskiĭ, Joseph P. Kennedy, Aleksandr F. Kerenskiĭ, Vladimir V. Nabokov, Fedor I. Shali︠a︡pin, Petr and Gleb Struve, Adri︠a︡na V. Trykova-Williams etc. The remainder of the collection consists of manuscripts of articles and speeches both by Sablin and by others; public statements issued by Sablin in mimeograph form; miscellaneous mimeo material; clippings from both the Russian emigre press and British and French newspapers of articles by and about Sablin; as well as miscellaneous clippings, books, booklets, leaflets, performance programs, newsletters, Russian language newspapers published in England, photographs and several drawings and watercolor sketches.

The papers consist primarily of the Kosatkin-Rostovskiĭ's memoirs. His manuscript memoirs (150 p.) discuss his life up to 1906. Her typescript memoirs (440 p.) discuss her childhood, career as an actress in St. Petersburg, 1917-1918 in Petrograd, and the emigration in France. Also included are his diary for June-July 1940; a few letters written to him; clippings of his newspaper articles (many signed with the pseudonym "Antar"); and a book with his poetry and with essays dedicated to him; "Krestnym putem k voskresenii︠u︡" (Paris, 1948).

The papers consist of correspondence, manuscripts, photographs, a subject file, and printed materials. The correspondence includes a letter from Randall Thomas Davidson, Archbishop of Canterbury, and one from Nikolaĭ Roerich. There is an essay about Metropolitan Platon by I︠O︡ann Chepelev, and a number of photographs depicting church officials and White army leaders. There is a subject file concerning Platon's meeting in 1919 with President Wilson. The collection also contains articles and clippings by and about the Metropolitan, and there are several books and pamphlets as well. The materials were collected by his daughter and grandson; many of the items are photocopies.

The collection contains Simonovich's correspondence, manuscripts, doucments, subject files, and printed materials. There are letters to Simonovich from a friend who had settled in Yugoslavia, A. S. Poplavskiĭ, and Belgian postcards from before World War I. Manuscripts deal with Simonovich's experiences in the Imperial army on the Caucasian front and in the White army under general Slashchev. There are also essays devoted to the Russian emigre colonies in Belgium and in France. The subject files concern the Belgian section of the Gallipolian Society (Obʺshchestvo Gallipolit︠s︡ev) and Russian emigre events in Belgium. The printed materials include chiefly miscellaneous journals and clippings, some with articles by Simonovich.