Read the story of Hercules and the Cattle of Geryon, as told by Apollodorus, the ancient writer who collected legends in his mythology handbook, the Library.
The Temple of Zeus at Olympia was decorated with sculptures illustrating the Labors of Hercules. Look at the sculpture catalog entry for the Geryon metope.
Cattle were a sign of wealth in ancient Greece, for only a rich person could afford to feed and maintain a large herd. Read an early hymn to Mother Earth which describes the wealth of a man blessed by the Earth.