Türkiye – Great Britain: 1917 (18 April). Cover from British prisoner of war Leading Seaman G. McNamara of the Kitchener Recruit KP 408 to Hove, England struck by Haydarpasa Harbiye Hastahanesi (Military Hospital) datestamp, Istanbul 2 rectangular censor cachet and 6 July London arrival machine cancel. Very rare if not unique hospital postmark.
