Complex sentence: East Anglia was at this time one of the most densely populated areas in England, producing large amounts of grain, sheep, cattle and poultry; much of this produce was traded in Norwich, an inland port roughly at the centre of the region.
Split into simpler sentences: East Anglia was at this time one of the most densely populated areas in England, producing large amounts of grain, sheep, cattle and poultry. Much of this produce was traded in Norwich, an inland port roughly at the centre of the region.