The prazeros only rarely removed local chiefs on their estates , preferring to retain them as subordinates .
Few attempted to start commercial agriculture , but took the surplus products of chiefs ' peasants and also profited from the trade in ivory and slaves .
The prazeros only rarely removed local chiefs on their estates , preferring to retain them as subordinates , and few attempted to start commercial agriculture , but took the surplus products of their peasants and also profited from the trade in ivory and slaves .