A Swedish expression that refers to being courageous translates to having “rye in your back”, which to Swedes, is important in the journey of life.. For this venture, they packed a type of black bread that kept for a long time -  months rather than days.. This Nordic bread, which was introduced to the British Isles around 500 AD by the Saxons and Danes following the defeat of King Arthur, was considered well-suited to the colder northern climates and is served still today in thin slices because of its density.. Although the distinct flavor is sometimes diluted in order to appeal to more people, it is important to know that a real rye bread can never contain wheat flour..