Complex sentence: The forces of Ibrahim Pasha were extremely brutal in the Peloponnese, burning the major port of Kalamata to the ground and slaughtering the city's inhabitants; they also ravaged the countryside and were heavily involved in the slave trade.
Split into simpler sentences: The forces of Ibrahim Pasha were extremely brutal in the Peloponnese, burning the major port of Kalamata to the ground and slaughtering the city's inhabitants. They also ravaged the countryside and were heavily involved in the slave trade.