Cadmus

He came from Phoenicia looking for his sister and ended up founding a civilization.
Cadmus is the son of King Agenor, brother of Europa whose abduction by Zeus sent him wandering across the Greek world on an impossible search. When the oracle at Delphi told him to stop searching and follow a cow instead, he obeyed. The cow led him to Boeotia. He killed the dragon that guarded the sacred spring. He sowed the dragon's teeth and armed men rose from the earth. From those five survivors - the Spartoi, the Sown Men - he built Thebes.
Cadmus is the interior account of one of the ancient world's most consequential founders - the man who introduced the Phoenician alphabet to Greece and set in motion the entire subsequent tradition of Western literacy, who married Harmonia at a wedding attended by all the gods, and who watched his children suffer through some of the most devastating stories in the Greek mythological tradition.
He brought the alphabet from Sidon. He built the city on the plain where the cow lay down. He and Harmonia were transformed into serpents at the end, together, as they had been together through everything else.
The dragon he killed became the city he built. This is that story.