Complex sentence: Fiach escaped with the loss of two sisters and two foster brothers and in retaliation led 400 followers in raids on villages in Wexford, managing to retire to Glenmalure after evading the seneschal's forces.
Split into simpler sentences: Fiach escaped with the loss of two sisters and two foster brothers. In retaliation he led 400 men in raids on villages in Wexford, managing to retire to Glenmalure after evading the seneschal's forces.