Complex sentence: Even before Poltava, Tolstoy had the greatest difficulty in preventing the Turks from aiding the Swedes, and when Charles XII took refuge on Turkish soil he instantly demanded his extradition.
Split into simpler sentences: Even before Poltava, Tolstoy had the greatest difficulty in preventing the Turks from aiding the Swedes. When Charles XII took refuge on Turkish soil Tolstoy, instantly demanded his extradition.