In William St. Clair’s fascinating, and very well documented book Lord Elgin & The Marbles; the controversial history of the Parthenon sculptures (third revised edition, 1998) one can read an account about the illicit removal of ancient manuscripts: “Professor Carlyle had been attached to Lord Elgin’s Embassy by the government for the specific purpose of looking for ancient manuscripts”…”Carlyle obtained them in various ways. Six he brought from the monastery of St Saba near Jerusalem. Four or five others come from the library of the Patriarch of Jerusalem at Constantinople. To none of these manuscripts did Carlyle have any legal title. They were lent to him, at his own insistent request, to allow them to be collated in England and to help with the production of a revised edition of the New Testament. Before he left Constantinople for the last time in March 1801 Carlyle signed a declaration prepared by the Patriarch promising to return the manuscripts to the Patriarch at Constantinople ‘when the purposes for which they were borrowed were completed or whenever the Patriarch should demand them’. Philip Hunt, as a secretary of the Embassy also signed the declaration, thus making the British Government a party to the promise”. (Chapter 21 The fate of the manuscripts, of St. Clair’s book.)
These manuscripts were never returned. Apparently ‘the purposes for which they were borrowed’ are still – after 200 years – to be completed…
Where are they now: in the library of the Archbishop of Canterbury’s Library at Lambeth.
Correct me if I am wrong, but if I remember well Carlyle also took manuscripts form the monastery of Mount Athos.