The documents include official papers of Count Henry de Nassau d'Auverquerque as Master of the Horse to William III, and a small number of items in connection with his position as Field Marshall of the Dutch forces and as Captain of the King's Guard; some accounts of his household and that of his wife Frances Madame d'Auverquerque after his death; estate papers and accounts relating to Madame d'Auverquerque's administration of the affairs of her grandson the Earl of Bath; household and other accounts of the Earl of Grantham; and a large number of official and personal papers of Count William Maurice de Nassau, a military commander and governor of Sluys and Dutch Flanders, including financial papers, household accounts, voluminous correspondence and documents concerning Dutch military and civil administration.
The majority of the documents, except those concerning the Earl of Bath's estates, are in Dutch, but a considerable number are in French. The description of each item or bundle includes mention of the language or languages in which it is written when this includes a language other than English. Dates should be assumed to be New Style in the case of those documents written on the Continent, and Old Style in the case of those written in England.
Many of the papers, in particular the bundles of Count William Maurice's correspondence, bear traces of one or more series of original numbers. These have been noted where found, although it is apparent that some of the bundles to which they relate have been broken up or otherwise tampered with.