Mysia was a region in northwestern Asia Minor and an important part of the Roman province of Asia. Its boundaries were imprecise, extending toward the Sea of Marmora, Bithynia, Phrygia, Lydia, and the Hellespont.
Paul passed through Mysia during his first journey toward Europe and continued to Troas, its coastal port, without stopping to preach there.
Important cities associated with the region included Assos, Troas, and Adramyttium. After Mysia became part of the Roman province of Asia, its old name fell into disuse and the region was generally called Hellespontus.