The prime purpose of this book is to edit and publish the principal surviving group of letters written by C. R. Cockerell while he was on his travels, between 1810 and 1817. These are preserved in the archive of the Royal Institute of British Architects (RIBA), purchased from Mrs Crichton in 1984. This material includes seven letters from Cockerell to his brother John; six to his sisters; eighteen (one actually written after his return but directly relevant) to his father, Samuel Pepys Cockerell; two to Robert Smirke; one to Sandford Graham; three from Samuel to Cockerell (again one after his return), and one to Samuel from Haller von Hallerstein, which are directly related to Cockerell's travels, giving a total of thirty-eight letters. The letters each carry a pencil note giving their reference number within the sequence RIBA COC: Add/1/1–43, and this appears at the head of each edited letter. Numbers 1/8, 1/32, 1/33, 1/42 and 1/43 in the RIBA numbers are omitted, since 1/8, 1/32, 1/42 and 1/43 do not relate to Cockerell's travels, and 1/33 to him from Carl Rester is too poorly preserved.

It is clear from internal evidence in the letters, that Cockerell wrote a number which never reached England, or perhaps did so long after they were written; some of these may have come into the possession of his fellow travellers and have not yet surfaced. It seems that the Cockerell papers, including probably some of the letters, were perhaps at different times scattered and in the possession of several of his descendants, and that these groups of papers had different histories, involving long retention in family hands, loans to museums, gifts, and sales to archives, particularly RIBA. Vickers refers to ‘letters … made by Charles Cockerell … during … his sojourn in Greece and Turkey’ preserved in the Greek and Roman Department of the British Museum, and was able to quote three, written from Pera in 1810, which are not currently available in the Museum, and the texts of which do not feature in the RIBA archive. Cockerell himself seems to have made copies of his letters, probably while he was away (although not of all, or at least not all survive) and at other points also copies seem to have been made of at least some of the letters, possibly not always complete copies.