Complex sentence: Hadjigeorgakis appointed his assistant, a man named Nicholaos Nicholaides, as his commissary who unfortunately was quick to take advantage of his position to become rich.
Split into simpler sentences: Hadjigeorgakis appointed his assistant, a man named Nicholaos Nicholaides, as his commissary. Nicholaides was quick to take advantage of his position to become rich.