IT'S the strange case of what happened to the publisher on his way home from meeting Agatha Christie in 1935.
He desperately wanted something to read on the rail journey home from Exeter to London and was so disappointed at what he found that he decided to fill the yawning gap by providing good quality fiction at an attractive price.
All that was left for Allen Lane, then a director of The Bodley Head, was to come up with a symbol that was "dignified but flippant".
It was his secretary Joan Coles who suggested a penguin and another employee Edward Young went to London Zoo to do the sketches.
Penguin Books was born and the paperback revolution was under way.
And when the first paperbacks came out in the summer of that year (priced at 6d (2½p) or the cost of a packet of cigarettes), the first authors were Ernest Hemingway, André Maurois - and Agatha Christie!
Famous authors like J B Priestley and George Bernard Shaw gave enthusiastic backing, George Orwell said more guardedly: "The Penguin Books are splendid value for sixpence, so splendid that if other publishers had any sense they would combine against them and suppress them."
Now Orwell's Animal Farm is the best-selling Penguin title of them all.
The books were colour coded: orange for fiction, blue for biography and green for crime. Today Pantone© 1505 is known the world over as Penguin Orange and Penguin is the only book brand recognised globally.
This fact was graphically driven home to Terry Waite when he was a hostage in Beirut. Terry drew a penguin as a way of asking his captors for some good books to read - and they understood!
By 1936 Penguin has become a separate company and a year later saw the launch of the Penguin Shakespeare series, the Pelican imprint and the appearance of the "Penguincubator" book-dispensing machine at Charing Cross.
When the Second World War came, the Penguin book Aircraft Recognition was used by the forces and civilians to identify enemy planes.
Penguin started the Armed Forces Book Club in 1942 and servicemen found the paperbacks would fit nicely in their pockets or in a kit bag. They were especially prized in PoW camps.
The 1940s also saw the introduction of Puffins for children and, in1946, another milestone in Penguin Classics.
In the 1960s the company found itself charged under the Obscene Publications Act 1960 in a major test case for publishing Lady Chatterley's Lover by D H Lawrence.
It was great publicity and when they were acquitted, amid huge queues Penguin sold 2m copies of the book in six weeks and when Penguin became a public company in 1961 it was 150 times oversubscribed - a London Stock Exchange record.
By the time the founder, then Sir Allen Lane, died in1970 there had been a new imprint named after him and Penguin were bought out by Pearson, the international media group.
But they have kept up Penguin's crusading zeal, publishing Salmon Rushdie's The Satanic Verses in the 1980s and more recently defending a libel suit by revisionist historian David Irving in 2000 after publishing Prof Deborah Lipstadt's Denying the Holocaust and in 2002 bringing out Michael Moore's Stupid White Men in the UK after attempts to ban it in the USA.