Lundy Island, situated off the north Devon coast, UK, had its own postal service launched on 1 November 1929 by Martin Coles Harman (UK), then-owner of the island.
The private postal service came about after the General Post Office left the island in 1927 after 50 years. For the next two years Harman ferried the post to mainland Britian, launching the puffin post to cut his costs (Lundy is the Old Norse word for puffin). The stamps all feature a puffin or puffins and come in various denominations.
Comments below may relate to previous holders of this record.