Complex sentence: In 1073, after a strong siege, it was burned by Robert Guiscard; soon after it was sacked by the Pisans, by Ottone Brunswich (1210) and by the Sicilians, after the famous Sicilian Vespers (1283).
Split into simpler sentences: In 1073, after a strong siege, it was burned by Robert Guiscard. Soon after, it was sacked by the Pisans, by Ottone Brunswich (1210), and by the Sicilians in (1283).