Complex sentence: In 1182 it fell to Saladin, whose nephew recovered it when it had temporarily passed (1234) to the sultan of Rum; but the "Eye of Mesopotamia" never recovered the brilliance of earlier days.
Split into simpler sentences: In 1182 it fell to Saladin, whose nephew recovered it when it had temporarily passed (1234) to the sultan of Rum. But the "Eye of Mesopotamia" never recovered the brilliance of earlier days.