In Greek myth, Leda was the daughter of King Thestius of
Aetolia. She was the wife of Tyndareus, king of Sparta and the
mother of Clytemnestra and Helen of Troy (among others). It is
said that Zeus was attracted to her and approached her in the
form of a swan. Things then get a little complicated - stories
vary as to the offspring of that union; Helen is thought to be
one. There was either an egg involved or there was not. The
story of Leda has been perpetuated in Art more than by word,
with ”Leda and the Swan” being a favourite subject since ancient
times.