Every December, a huge Christmas tree arrives in Trafalgar Square. Bedecked in lights, it is a shimmering, festive beacon in the heart of London. But even more enchanting than the twinkling decorations and scented pine is the story behind the tree; a story of loyalty, friendship and resistance. On a cold evening in 1940, German w arships made their w ay tow ards Oslo. It seemed inevitable that Norw ay, like so many other European nations, w ould soon...