Once upon a time, there was a great Swan King, who ruled together with his wife. They had a son, a fair Prince known as Siegfried. When the foul Raven appeared, the King challenged the Raven together with his Swan Queen to defend the kingdom. However, both were struck down.
 The Prince was distraught, but he knew what he must do, and resolved to continue fighting for the sake of his kingdom. It was then that a pair of swans appeared to him (or something, THIS IS the bit I really need to work out and make less silly), and spoke to him as his parents. The promised to be with him always, and his father made him promise in return to defend the kingdom with all his heart. And his mother, though she greatly valued the kingdom as well, feared what such a sacrifice would bring her son, and so she forbade him to do so. Once they had given him these words, they (another fuzzy bit here) flew to decorate the prince's sword, and serve as his strength whenever he might call for them.