Achilles the best fighter of the Greeks who besieged Troy in the Trojan War; extraordinarily strong, courageous, and loyal, he had only one weak spot: his heel
Admetus the king of Pherae in Thessaly; Zeus punished Apollo by sending him to work for Admetus as a shepherd
Aeolus the Greek god of the winds
Agamemnon king of Mycenae; the leader of the Greeks in the Trojan War; courageous, but also arrogant and overly proud
agora Greek for gathering place; a central outdoor spot for athletic, artistic, spiritual, and political life in ancient Greek city-states
Ajax Greek hero with great strength and courage; fought in the Trojan War; used a large shield in battle
ambrosia food of the gods; has healing powers
amphitheater an oval or circular open-air space used for performances or sporting events, with spectator seating built in a semicircle around the
stage
Aphrodite the Greek goddess of love and beauty
apodesmos a band of material that women in ancient Greece wore around the chest, particularly while participating in sports
Apollo the Greek god of the sun, prophecy, music, and healing; the son of Zeus and Leto, and the twin of Artemis
Ares the Greek god of war; the son of Zeus and Hera, and half brother to Athena
Argo the ship used by a band of heroes who accompanied Jason on his quest to find the Golden Fleece
Argonauts a band of heroes who sailed with Jason on the Argo, in search of the Golden Fleece
Artemis the Greek goddess of the hunt and the moon; the daughter of Zeus and Leto, and the twin of Apollo
Asclepius the god of medicine; son of Apollo; his temple was the healing center of ancient Greece
Athena the Greek goddess of wisdom
Athena Parthenos a giant statue of Athena; the most famous Greek statue of all time
ballista (ballistae, pl.) a Roman missile siege weapon that launched a large projectile at a distant target
Batavi an ancient tribe that lived in modern-day Germany; also an infantry unit in the Roman army with Germanic origins
Briseis a princess captured by Achilles during the Trojan War, causing a feud between Achilles and Agamemnon that resulted in Achilles refusing to fight alongside the Greeks
Bunker Nine a hidden workshop Leo Valdez discovered at Camp Half- Blood, filled with tools and weapons; it is at least two hundred years old and was used during the Demigod Civil War
Caesar Augustus the founder and first emperor of the Roman Empire; adopted son and heir of Julius Caesar (see also Octavian)
Calliope the muse of epic poetry; mother of several sons, including Orpheus
Calypso the goddess nymph of the mythical island of Ogygia; a daughter of the Titan Atlas; she detained the hero Odysseus for many years
Camp Half-Blood the training ground for Greek demigods, located in Long Island, New York
Camp Jupiter the training ground for Roman demigods, located between the Oakland Hills and the Berkeley Hills, in California
Cassandra the daughter of King Priam and Queen Hecuba; had the gift of prophecy, but was cursed by Apollo so that her predictions were never
believed, including her warning about the Trojan Horse
catapult a military machine used to hurl objects
Cave of Trophonius a deep chasm home to the Oracle Trophonius; its extremely narrow entrance required a visitor to lie flat on his back before being sucked into the cave; called “The Cave of Nightmares” due to the terrifying accounts of its visitors
Celestial bronze a rare metal deadly to monsters
centaur a race of creatures that is half-human, half-horse
Ceres the Roman god of agriculture; Greek form: Demeter
Chiron a centaur; the camp activities director at Camp Half-Blood
chiton a Greek garment; a sleeveless piece of linen or wool secured at the shoulders by brooches and at the waist by a belt
Chrysothemis a daughter of Demeter who won Apollo’s love during a music contest
Circe a Greek goddess of magic
Cloacina goddess of the Roman sewer system
Clytemnestra the daughter of the king and queen of Sparta; married and later murdered Agamemnon
Colosseum an elliptical amphitheater in the center of Rome, Italy, capable of seating fifty thousand spectators; used for gladiatorial contests and
public spectacles such as mock sea battles, animal hunts, executions, re- enactments of famous battles, and dramas
Colossus Neronis (Colossus of Nero) a gigantic bronze statue of Emperor Nero; was later transformed into the sun god with the addition of a sunray crown
Cretan of the island of Crete
Crommyon a village in ancient Greece where a giant wild sow wreaked havoc before it was killed by Theseus
cuirass leather or metal armor consisting of a breastplate and backplate worn by Greek and Roman soldiers; often highly ornamented and designed to mimic muscles
Cyclops (Cyclopes, pl.) a member of a primordial race of giants, each with a single eye in the middle of his or her forehead
Cyrene a fierce huntress with whom Apollo fell in love after he saw her wrestle a lion; Apollo later transformed her into a nymph in order to extend her life
Daedalus a skilled craftsman who created the Labyrinth on Crete in which the Minotaur (part man, part bull) was kept
Daphne a beautiful naiad who attracted Apollo’s attention; she was transformed into a laurel tree in order to escape him
Demeter the Greek goddess of agriculture; a daughter of the Titans Rhea and Kronos; Roman form: Ceres
dimachaerus a Roman gladiator trained to fight with two swords at once
Dionysus the Greek god of wine and revelry; the son of Zeus; activities director at Camp Half-Blood
Domus Aurea Emperor Nero’s extravagant villa in the heart of ancient Rome, built after the Great Fire of Rome
Doors of Death the doorway to the House of Hades, located in Tartarus; doors have two sides—one in the mortal world, and one in the Underworld
drakon a gigantic yellow-and-green serpentlike monster, with frills around its neck, reptilian eyes, and huge talons; it spits poison
dryads tree nymphs
Erebos a place of darkness between earth and Hades
Eros the Greek god of love
Erythaea an island where the Cumaean Sibyl, a love interest of Apollo, originally lived before he convinced her to leave it by promising her a long life
Fields of Punishment the section of the Underworld where people who were evil during their lives are sent to face eternal punishment for their crimes after death
Gaea the Greek earth goddess; mother of Titans, giants, Cyclopes, and other monsters
Germani (Germanus, sing.) tribal people who settled to the west of the Rhine river
Golden Fleece this hide from a gold-haired winged ram was a symbol of authority and kingship; it was guarded by a dragon and fire-breathing bulls; Jason was tasked with obtaining it, resulting in an epic quest
Gorgons three monstrous sisters (Stheno, Euryale, and Medusa) who have hair of living, venomous snakes; Medusa’s eyes can turn the beholder to stone
Great Fire of Rome a devastating fire that took place in 64 CE, lasting for six days; rumors indicated that Nero started the fire to clear space for the
building of his villa, Domus Aurea, but he blamed the Christian community for the disaster
greaves shin armor
Greek fire an incendiary weapon used in naval battles because it can continue burning in water
Grove of Dodona the site of the oldest Greek Oracle, second only to the Delphi; the rustling of trees in the grove provided answers to priests and priestesses who journeyed to the site
Hades the Greek god of death and riches; ruler of the Underworld
harpy a winged female creature that snatches things
Hebe the Greek goddess of youth; daughter of Zeus and Hera
Hecate goddess of magic and crossroads
Hephaestus the Greek god of fire and crafts and of blacksmiths; the son of Zeus and Hera, and married to Aphrodite
Hera the Greek goddess of marriage; Zeus’s wife and sister
Hermes Greek god of travelers; guide to spirits of the dead; god of communication
Herodotus a Greek historian known as the “Father of History”
Hestia Greek goddess of the hearth
hippocampi (hippocampus, sing.) half-horse, half-fish creatures
hippodrome an oval stadium for horse and chariot races in ancient Greece
Hittites a group of people who lived in modern Turkey and Syria; often in conflict with Egyptians; known for their use of chariots as assault
weapons
House of Hades a place in the Underworld where Hades, the Greek god of death, and his wife, Persephone, rule over the souls of the departed
Hunters of Artemis a group of maidens loyal to Artemis and gifted with hunting skills and eternal youth as long as they reject men for life
Hyacinthus a Greek hero and Apollo’s lover, who died while trying to impress Apollo with his discus skills
Hypnos the Greek god of sleep
ichor the golden fluid that is the blood of gods and immortals
imperator a term for commander in the Roman Empire
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
Polyphemus the gigantic one-eyed son of Poseidon and Thoosa; one of the Cyclopes
Poseidon the Greek god of the sea; son of the Titans Kronos and Rhea, and brother of Zeus and Hades
praetor an elected Roman magistrate and commander of the army
Primordial Chaos the first thing ever to exist; a void from which the first gods were produced
Prometheus the Titan who created humans and gifted them with fire stolen from Mount Olympus
Pythia the name given to every Oracle of Delphi
Python a monstrous serpent that Gaea appointed to guard the Oracle at Delphi
Rhea Silvia the queen of the Titans, mother of Zeus
Riptide the name of Percy Jackson’s sword; Anaklusmos in Greek
River Styx the river that forms the boundary between earth and the Underworld
Saturnalia an ancient Roman festival celebrating Saturn (Kronos)
satyr a Greek forest god, part goat and part man
shadow-travel a form of transportation that allows creatures of the Underworld and children of Hades to use shadows to leap to any desired place on earth or in the Underworld, although it makes the user extremely fatigued
Sibyl a prophetess
Sibylline Books a collection of prophecies in rhyme written in Greek; Tarquinius Superbus, a king of Rome, bought them from a prophetess and consulted them in times of great danger
siccae a short curved sword used for battle in ancient Rome Sparta a city-state in ancient Greece with military dominance Stygian iron a magical metal, forged in the River Styx, capable of
absorbing the very essence of monsters and injuring mortals, gods, Titans, and giants; has a significant effect on ghosts and creatures from the Underworld
Talos a giant mechanical man made of bronze and used on Crete to guard its shoreline from invaders
Tantalus According to legend, this king was such a good friend of the gods that he was allowed to dine at their table—until he spilled their
secrets on earth; he was sent to the Underworld, where his curse was to
be stuck in a pool of water under a fruit tree, but never be able to drink or eat
Tartarus husband of Gaea; spirit of the abyss; father of the giants; a region of the Underworld
Theodosius the last to rule over the united Roman Empire; known for closing all ancient temples across the empire
Thracian of Thrace, a region centered on the modern borders of Bulgaria, Greece, and Turkey
Titan War the epic ten-year battle between the Titans and the Olympians that resulted in the Olympians taking the throne
Titans a race of powerful Greek deities, descendants of Gaea and Ouranos, that ruled during the Golden Age and were overthrown by a race of younger gods, the Olympians
trireme a Greek warship, having three tiers of oars on each side
triumvirate a political alliance formed by three parties
Trojan War According to legend, the Trojan War was waged against the city of Troy by the Achaeans (Greeks) after Paris of Troy took Helen from her husband, Menelaus, king of Sparta
Troy a Roman city situated in modern-day Turkey; site of the Trojan War
Tyche the Greek goddess of good fortune; daughter of Hermes and Aphrodite
Typhon the most terrifying Greek monster; father of many famous monsters, including Cerberus, the vicious multi-headed dog tasked with
guarding the entrance to the Underworld
Underworld the kingdom of the dead, where souls go for eternity; ruled by Hades
Zephyros the Greek god of the West Wind
Zeus the Greek god of the sky and the king of the gods
