Complex sentence: At this period, just after Battle of Waterloo, Britain and its Empire were at peace and shipping large numbers of English and Irish convicts to the colony of New South Wales where they were the main source of labour.
Split into simpler sentences: At this period, just after Battle of Waterloo, Britain and its Empire were at peace. Large numbers of English and Irish convicts were being shipped to the colony of New South Wales where they were the main source of labour.