Peloponnesos (Greek: Πελοπόννησος, sometime Latinized as Peloponnesus or Anglicized as The Peloponnese) is a large peninsula in Greece, forming the part of the country south of the Isthmus of Corinth.
Its name derives from the Ancient Greek Mythological Hero, 'Pelops', who supposedly conquered the entire region. Of the name, Peloponnesos, 'Pelop' refers to this hero and 'nesos' refers to island, therefore the name means the Island of Pelops. However, Peloponnesos only became a true island with the creation of the Corinthian Canal in 1893. In 2004 Peloponnesos gained a second connection to the mainland, with the completion of the Rio-Antirio bridge.
At this time, Heracles 1 was campaigning in the Peloponessus; he had already captured Elis, and after attacking Pylos, he killed Neleus and his sons except Nestor.
When Pylos was taken, Heracles 1 marched against Lacedaemon, because the Lacedaemonians had supported the Pylians in their war against Heracles 1, and also because he wished to punish the sons of Hippocoon 2 for the death of Oeonus.