An engaging collection of Antarctic and maritime postal history centred on RRS John Biscoe, the British Antarctic Survey research and supply ship that served from 1956 to 1991, transporting scientists, equipment and supplies to remote Antarctic stations. The lot brings together correspondence from different postal origins, including Great Britain, the British Antarctic Territory, the Falkland Islands, East Germany, Poland, France and Austria. The covers feature varied frankings, ship cachets, Antarctic station markings and handwritten signatures. A prominent feature is the extensive returned and redirected mail, with endorsements such as “RETURN TO SENDER”, “ADDRESSEE UNKNOWN”, “INCONNU / NOT KNOWN” and “RTS”. Crossed-out addresses and forwarding instructions illustrate the challenges of delivering mail to research vessels and isolated stations. Selected highlights include: • Pitcairn Islands: correspondence addressed to the General Post Office on Pitcairn, bearing the John Biscoe “Antarctic Relief Voyage 1984–1985” cachet. • Signy Island: a cover with the vessel’s rectangular identification handstamp and a separate “SIGNY ISLAND” marking. • Signed John Biscoe correspondence: a cover bearing the seabird cachet inscribed “1956–1991”, handwritten signatures and return instructions. • Rothera: an internationally franked cover with Antarctic markings and a clear “RETURN TO SENDER” endorsement. • East German Antarctic research: a cover combining the DDR Antarctic research station commemorative cancellation with a John Biscoe seasonal cachet and an “ADDRESSEE UNKNOWN” return marking. • South Georgia and Halley: a cover with the King Edward Point cachet, a Port Stanley cancellation and an address referring to Halley in the British Antarctic Territory. Tax-related markings and manuscript figures on some items provide additional interest for the study of postage due—charges potentially payable by the recipient. Their presence does not, by itself, establish that the charge was collected. Further markings relate to Antarctic stations including Halley, Signy, Faraday and Rothera, alongside other maritime connections and ship cachets. Condition varies, with folds, toning, opening wear, address cancellations and other signs of postal handling. Signatures are offered as present, without separate authentication. Please examine all photographs carefully. Front and reverse views show the same items; close-up photographs illustrate selected highlights and are not additional I can combine the shippings strictly following the Catawiki rules. Following a recent change in international sector regulations, specifically Articles 18 and 19 of the Universal Postal Convention, starting from January 1, 2026, it will no longer be possible to send items (goods with or without commercial value) using International Registered and International Insured services, which will continue to be used exclusively for sending documents. It means that starting from January 1st, 2026, I will ship abroad only by "POSTE DELIVERY INTERNATIONAL STANDARD" starting from 25,80€ without insurance