Complex sentence: When his brother Miroslav took over, he expelled bishop Donat from Ston and orthodox priests arrived to Peljesac while the Catholic population was taken provided for by the Benedictine monks from the island Mljet.
Split into simpler sentences: When his brother Miroslav took over, he expelled bishop Donat from Ston and orthodox priests arrived to Peljesac. The Catholic population was then provided for by the Benedictine monks from the island Mljet.