Wikipedia
Pelasgiotis (Greek: ) was an elongated district of ancient Thessaly from the Vale of Tempe to the southern city of Pherae. Pelasgiotis included the below localities: Argos Pelasgikon, Argyra, Atrax, Crannon, Cynoscephalae, Elateia, Gyrton, Mopsion, Larissa, Kondaia, Onchestos river and town, Phayttos, Pherae, Skotoussa and Sykourion.
Phthiotis, Thessaliotis, Histiaeotis and Pelasgiotis comprised the Thessalian tetrarchy, governed under the title of tagus, when occasion required.
The territory is mentioned by Strabo but not by Herodotus, who seems to include it in the district of Thessaliotis. In epigraphy, Pelasgiotes are mentioned among other Thessalian ambassadors in Athens ca.353 BC. A fragment of a marble stele at Larissa in Thessaly records that on request of the consul Quintus Caecilius Metellus, son of Quintus, "friend and benefactor of our country (ethnei hēmōn)" in return for services rendered by him, his family and the S.P.Q.R., the Thessalian League decreed to send 43,000 coffers of wheat to Rome, to be taxed from different regions under the league. The Pelasgiōtai and the Phthiōtai are to provide 32,000 while the Histiōtai and Thessaliōtai must provide the remaining 11,000, with 25% going to the army, all in different months.
The regional and ethnic toponym is a reminiscent Pelasgian element from the Thessalian past . As in other parts of Thessaly, Aeolic Greek inscriptions are attested and after 2nd century BC, Koine Greek.
During the Thessalian Games at Larissa to Zeus Eleuthereus of 1st century BC, several winner athletes are named Thessalian from Larissa of Pelasgis or the Pelasgid . The 3rd century BC funerary epigram for Erilaos of Kalchedon mentions also Larisa tai Pelasgidi.