Complex sentence: The painting depicts the Roman goddess Diana, one of the twelve Gods and Goddesses of Olympus, falling in love with Endymion, the story depicts Diana's love for the beautiful youth Endymion.
Split into simpler sentences: The painting depicts the Roman goddess Diana, one of the twelve Gods and Goddesses of Olympus, falling in love with Endymion. The story depicts Diana's love for the beautiful youth Endymion.