Son of Orestes and Erigone

Penthilus (Πένθιλος) was the illegitimate son of half-siblings Orestes

Orestes (mythology)

In Greek mythology, Orestes was the son of Clytemnestra and Agamemnon. He is the subject of several Ancient Greek plays and of various myths connected with his madness and purification, which retain obscure threads of much older ones....

 and Erigone

Erigone (daughter of Aegisthus)

In Greek mythology Erigone was the daughter of Aegisthus and Clytemnestra, rulers of Mycenae. By her half-brother, Orestes, Erigone was the mother of Penthilus. She would have also been slain by Orestes along with her brother Aletes if not for the intervention of Diana, who rescued her and made her...

. Erigone was the daughter of Clytemnestra

Clytemnestra

Clytemnestra or Clytaemnestra , in ancient Greek legend, was the wife of Agamemnon, king of the Ancient Greek kingdom of Mycenae or Argos. In the Oresteia by Aeschylus, she was a femme fatale who murdered her husband, Agamemnon – said by Euripides to be her second husband – and the Trojan princess...

 and Aigisthos

Aegisthus

In Greek mythology, Aegisthus was the son of Thyestes and of Thyestes' daughter, Pelopia....

 (both of whom Orestes killed), while Orestes was the son of Clytemnestra and Agamemnon

Agamemnon

In Greek mythology, Agamemnon was the son of King Atreus and Queen Aerope of Mycenae, the brother of Menelaus, the husband of Clytemnestra, and the father of Electra and Orestes. Mythical legends make him the king of Mycenae or Argos, thought to be different names for the same area...

. Erigone is said to have hanged herself. Orestes was ruler over much of the Peloponnese and died of a snakebite at age 70. One story says that as a child, Penthilus was torn apart and devoured by wolves in the Taygetus

Taygetus

Mount Taygetus, Taugetus, or Taigetus is a mountain range in the Peloponnese peninsula in Southern Greece. The name is one of the oldest recorded in Europe, appearing in the Odyssey. In classical mythology, it was associated with the nymph Taygete...

 mountains, near Sparta. His father established a festival of mourning, the so-called Penthilia in his honour.

According to Pausanias

Pausanias (geographer)

Pausanias was a Greek traveler and geographer of the 2nd century AD, who lived in the times of Hadrian, Antoninus Pius and Marcus Aurelius. He is famous for his Description of Greece , a lengthy work that describes ancient Greece from firsthand observations, and is a crucial link between classical...

, Penthilus grew up and founded a city either on Lesbos or in Thrace

Thrace

Thrace is a historical and geographic area in southeast Europe. As a geographical concept, Thrace designates a region bounded by the Balkan Mountains on the north, Rhodope Mountains and the Aegean Sea on the south, and by the Black Sea and the Sea of Marmara on the east...

. His grandson Gras founded a city Aeolis

Aeolis

Aeolis or Aeolia was an area that comprised the west and northwestern region of Asia Minor, mostly along the coast, and also several offshore islands , where the Aeolian Greek city-states were located...

, between Ionia

Ionia

Ionia is an ancient region of central coastal Anatolia in present-day Turkey, the region nearest İzmir, which was historically Smyrna. It consisted of the northernmost territories of the Ionian League of Greek settlements...

 and Mysia

Mysia

Mysia was a region in the northwest of ancient Asia Minor or Anatolia . It was located on the south coast of the Sea of Marmara. It was bounded by Bithynia on the east, Phrygia on the southeast, Lydia on the south, Aeolis on the southwest, Troad on the west and by the Propontis on the north...

.

King of Messenia

Penthilus was also the name of a king of Messenia

Messenia

Messenia is a regional unit in the southwestern part of the Peloponnese region, one of 13 regions into which Greece has been divided by the Kallikratis plan, implemented 1 January 2011...

, son of Periclymenus

Periclymenus

In Greek mythology, the name Periclymenus may refer to:*A son of Neleus and Chloris. He was one of the Argonauts. Poseidon gave him the ability to shapeshift into various animals. He was killed by Heracles at Pylos, although he tried to escape in the form of an eagle. His offspring were Erginus...

 and father of Borus.