In England, Swans are a symbol of loyalty and strength. In many European fairytales, they smbolize chastity because of their color, artistry and beauty.
Swans were sacred to Aphrodite and Apollo. It was sacred to Aphrodite because of their beauty and to Apollo because of music. It was believed swans let out beautiful songs when people died, and it would be the most beautiful song they would ever sing.
They also smybolize power, because of the power and beauty we can awaken in ourselves, as illustrated in the tale "The Ugly Duckling."