Leslie A. Marchand's great edition of Byron's letters and journals, published between 1973 and 1981, included every letter then available, all of them unbowdlerized and many published for the first time. Richard Holmes called it 'a beautifully produced edition ... which represent[s] in raciness, self-portraiture, scandal, intelligence and sheer devilish charm one of the great flowerings of English Romantic prose'. Ifor Evans described it as 'one of the great publishing ventures of our time'.

Since 1981, further letters have come to light and they are now published here. Many are newly discovered, some have been partially published but are here made complete from manuscripts, a few have been published in inaccessible periodicals.

All of them have biographical significance and many are of great interest, touching as they do on such diverse aspects of Byron's life as his journey to Greece, the infatuation of Lady Falkland (who believed he had written the Thyrza poems to her), and his liaison with Lady Caroline Lamb. The appearance of this volume brings up to date the publication of all the known letters of Byron.

In contrast to the Prothero edition, which included 1,198, Leslie Marchand prints some 3,000, more than 80 per cent of them transcribed in full from the original manuscripts.