Complex sentence: Despite several royal inspectors ("visitadores ") sent to improve its function, its performance did not improve, so executive power was centralized in one officer, the Audiencia"president," who was also made governor and captain general in 1564.
Split into simpler sentences: Despite several royal inspectors ("visitadores ") sent to improve its functioning, its performance did not improve. So executive power was centralized in one officer, the Audiencia"president", who was also made governor and captain general in 1564.