Agrinio is the link connecting Aitolia and Akarnania...

The position of the city in Aitoloakarnania is defined by the presence of the river named after the ancient god "Acheloos".  The city has a long history, as it was inhabited since the prehistoric period. Agrinio is the largest city of the prefecture of Aitoloakarnania and has a population of 90.000 residents.

Gerasimos Papatrehas, the historian of Agrinio, writes about the mythology of the region:

"The tradition of Agrios, a hero and primogenitor of the region, was honored by the residents of Agrinio". In his book "History of Agrinio", Gerasimos Papatrehas narrates the myth of Agrios, which dates back to the post-Hellenic period (1600-1100 B.C):

"Agrios was the son of Portheas and descendant of the hero Aitolos, the leader of the people of Aitolia.  But let's travel back, as much as we can, to the Aitolian mythological circle to unravel the genealogical tree of this royal family. The wealthy city of Ilida was ruled by the king Endymion, the son of Aethlios (or of Zeus) and Kalyki. His wife was Yperippi, daughter Arkados, or of Zisos. They had three sons, Epeios, Aitolos and Paion. When the sons reached adulthood, the old king Endymion decided to assign his throne to the most worthy of his sons. Therefore, he organized a running contest in Olympia, and he declared that the winner would take the throne. The winner of the contest was Epeios, who then became the king. Later, Aitolos took the throne for a short period of time, but he had to flee the city when he killed Atis, the son of the king of Argos, Foroneas. Chased by the sons of his victim, he crossed the passage of Rios and became the leader of Kourites. As he was the leader of the region, he named the country after him. He married Pronoi, the daughter of Forthos, and had two sons, Kalydonas and Plevronas. After the death of Aitolos, his son Plevronas and his generation dominated, however, the city founded by Kalydonas maintained his name. The son of Plevronas, Aginor, inherited his throne and married Epikasti and his son Porthaon or Pordeus dominated Kalydona. He had three sons and a daughter with his wife Eurity, Agrios, Oineas and Steropi. His daughter Steropi became the wife of Acheloos. Agrios had many sons, and the names of Oghistis, Thersitis, Prodoos, Keleutor, Lykopeus and Melanippos are recorded. The six sons decided that the old Oineas was not worthy of possessing the throne of Kalydona and replaced him with their father. According to Apollodoros, Oineas was imprisoned and tortured. However, the great Diomidis of Argos (the grandson of Oineas) came to take revenge. He killed the sons of the usurper and reclaimed the throne of his grandfather, who came back to power. Agrios survived and escaped to the northwest part of Aitolia where he founded a city named after him.

In one of the multiple editions of the myth, Agrios was the one who took revenge, when his nephew Tydeas, son of Oineas and father of Diomidis, killed his brother Olenias, or his cousins, sons of Melana. According to this edition, Agrios hunted Tydeas and obliged him to flee Kalydona and take refuge in Argos. There, Tydeas married the daughter of Adrastos, Diipyli who gave birth to Homer's hero, Diomidis.