Complex sentence: In 1025, Boiannes, who had been busy on a Sicilian expedition, joined them with a giant force and, in 1026, the city fell and the count of Teano was given safe passage to Naples by the Greek commander.
Split into simpler sentences: In 1025, Boiannes, who had been busy on a Sicilian expedition, joined them with a huge force. The count of Teano was given safe passage to Naples by the Greek commander.