Complex sentence: This proved ineffective, since when the King fled to Euesperides during the anticipated revolution (around 440 BC), he was assassinated, thus terminating the almost two hundred-year rule of the Battiad dynasty.
Split into simpler sentences: This proved ineffective because when the King fled to Euesperides during the anticipated revolution (around 440 BC), he was assassinated. Ultimately, this terminated the almost two hundred-year rule of the Battiad dynasty.