Achaeus was, according to nearly all traditions, a son of Xuthus

Xuthus

In Greek mythology, Xuthus was a son of Hellen and Orseis and founder of the Achaean and Ionian nations. He had two sons by Creusa: Ion and Achaeus and a daughter named Diomede.- Hesiod :...

 and Creusa

Creusa

In Greek mythology, four people had the name Creusa ; the name simply means "princess".-Naiad:According to Pindar's 9th Pythian Ode, Creusa was a naiad and daughter of Gaia who bore Hypseus, King of the Lapiths to the river god Peneus. Hypseus had one daughter, Cyrene. When a lion attacked her...

, and consequently a brother of Ion and grandson of Hellen

Hellen

Hellen , the son of Deucalion and Pyrrha, brother of Amphictyon and father of Aeolus, Xuthus, and Dorus. His name is also another name for Greek, meaning a person of Greek descent or pertaining to Greek culture, and the source of the adjective "Hellenic".Each of his sons founded a primary tribe of...

. The Achaea

Achaea

Achaea is one of the regional units of Greece. It is part of the region of West Greece. It is situated in the northwestern part of the Peloponnese peninsula. The capital is Patras. The population exceeds 300,000 since 2001.-Geography:...

ns regarded him as the author of their race, and derived from him their own name as well as that of Achaia, which was formerly called Aegialus. When his uncle Aeolus

Aeolus

Aeolus was the ruler of the winds in Greek mythology. In fact this name was shared by three mythic characters. These three personages are often difficult to tell apart, and even the ancient mythographers appear to have been perplexed about which Aeolus was which...

 in Thessaly

Thessaly

Thessaly is a traditional geographical region and an administrative region of Greece, comprising most of the ancient region of the same name. Before the Greek Dark Ages, Thessaly was known as Aeolia, and appears thus in Homer's Odyssey....

, whence he himself had come to Peloponnesus, died, he went thither and made himself master of Phthiotis

Phthiotis

Phthiotis is one of the regional units of Greece. It is part of the administrative region of Central Greece. The capital is the city of Lamia. It is bordered by the Malian Gulf to the east, Boeotia in the south, Phocis in the south, Aetolia-Acarnania in the southwest, Evrytania in the west,...

, which now also received from him the name of Achaia. Servius alone calls Achaeus a son of Jupiter

Jupiter (mythology)

In ancient Roman religion and myth, Jupiter or Jove is the king of the gods, and the god of the sky and thunder. He is the equivalent of Zeus in the Greek pantheon....

 (Zeus

Zeus

In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus...

) and Pithia, which is probably miswritten for Phthia, compare the account of Clement

Clement of Alexandria

Titus Flavius Clemens , known as Clement of Alexandria , was a Christian theologian and the head of the noted Catechetical School of Alexandria. Clement is best remembered as the teacher of Origen...

.