Complex sentence: The Valley of Solsken was not satisfied with their land and took over the Valley of Whispering Winds, the people who inhabited the Valley of Whispering Winds were taken as slaves.
Split into simpler sentences: The Valley of Solsken was dissatisfied with their land and took over the Valley of Whispering Winds. As a consequence to this take over, the people who inhabited the Valley of Whispering Winds were taken as slaves.