Imperial gold a rare metal deadly to monsters, consecrated at the Pantheon; its existence was a closely guarded secret of the emperors Iris the Greek goddess of the rainbow, and a messenger of the gods

Julian dynasty the time period measured from the battle of Actium (31 BCE) to the death of Nero (68 CE) karpoi (karpos, sing.) grain spirits kouretes armored dancers who guarded the infant Zeus from his father, Kronos Kronos the youngest of the twelve Titans; the son of Ouranos and Gaea; the father of Zeus; he killed his father at his mother’s bidding; Titan lord of fate, harvest, justice, and time; Roman form: Saturn Labyrinth an underground maze originally built on the island of Crete by the craftsman Daedalus to hold the Minotaur Laomedon a Trojan king whom Poseidon and Apollo were sent to serve after they offended Zeus Lepidus a Roman patrician and military commander who was in a triumvirate with Octavian and Marc Antony Leto mother of Artemis and Apollo with Zeus; goddess of motherhood

Lupercalia a pastoral festival, observed on February 13 through 15, to avert evil spirits and purify the city, releasing health and fertility Lydia a province in ancient Rome; the double ax originated there, along with the use of coins and retail shops Marc Antony a Roman politician and general; part of the triumvirate, with Lepidus and Octavian, who together tracked down and defeated Caesar’s killers; had an enduring affair with Cleopatra Marsyas a satyr who lost to Apollo after challenging him in a musical contest, which led to Marsyas being flayed alive Medea a follower of Hecate and one of the great sorceresses of the ancient world

Midas a king with the power to transform anything he touched to gold; he selected Marsyas as the winner in the musical contest between Apollo and Marsyas, resulting in Apollo giving Midas the ears of a donkey Minos king of Crete; son of Zeus; every year he made King Aegus pick seven boys and seven girls to be sent to the Labyrinth, where they would be eaten by the Minotaur; after his death he became a judge in the Underworld Minotaur the half-man, half-bull son of King Minos of Crete; the Minotaur was kept in the Labyrinth, where he killed people who were sent in; he was finally defeated by Theseus Mithridates king of Pontus and Armenia Minor in northern Anatolia (now Turkey) from about 120 to 63 BCE; one of the Roman Republic’s most formidable and successful enemies, who engaged three of the prominent generals from the late Roman Republic in the Mithridatic Wars Mount Olympus home of the Twelve Olympians

myrmeke a giant antlike creature that poisons and paralyzes its prey before eating it; known for protecting various metals, particularly gold Nemesis the Greek goddess of revenge

Nero Roman emperor from 54 to 68 CE; the last in the Julian dynasty New Rome a community near Camp Jupiter where demigods can live together in peace, without interference from mortals or monsters Nike the Greek goddess of strength, speed, and victory

Nine Muses Greek goddesses of literature, science, and the arts, who have inspired artists and writers for centuries Niobe daughter of Tantalus and Dione; suffered the loss of her six sons and six daughters, who were killed by Apollo and Artemis as a punishment for her pride nosoi (nosos, sing.) spirits of plague and disease nymph a female nature deity who animates nature

Octavian the founder and first emperor of the Roman Empire; adopted son and heir of Julius Caesar (see also Caesar Augustus) Odysseus legendary Greek king of Ithaca and the hero of Homer’s epic poem The Odyssey

Ogygia the island home—and prison—of the nymph Calypso

omphalus stones used to mark the center—or navel—of the world

Oracle of Delphi a speaker of the prophecies of Apollo

Oracle of Trophonius a Greek who was transformed into an Oracle after his death; located at the Cave of Trophonius; known for terrifying those who seek him Ouranos the Greek personification of the sky; father of the Titans

palikoi (palikos, sing.) twin sons of Zeus and Thaleia; the gods of geysers and thermal springs Pan the Greek god of the wild; the son of Hermes

Pandora the first human woman created by the gods; endowed with a unique gift from each; released evil into the world by opening a jar Parthenon a temple dedicated to the goddess Athena located at the Athenian Acropolis in Greece Patroclus son of Menoetius; he shared a deep friendship with Achilles after being raised alongside him; he was killed while fighting in the Trojan War pegasus (pegasi, pl.) a winged divine horse; sired by Poseidon, in his role as horse-god Peleus father of Achilles; his wedding to the sea-nymph Thetis was well attended by the gods, and a disagreement between them at the event eventually lead to the Trojan War; the guardian dragon at Camp Half-Blood is named after him Persephone the Greek queen of the Underworld; wife of Hades; daughter of Zeus and Demeter

phalanx (phalanxes, pl.) a compact body of heavily armed troops Phidias a famous ancient Greek sculptor who created the Athena Parthenos and many others