1911 Encyclopædia Britannica (1911)
“ Chalcis subsequently became a member of both the Delian Leagues. In the Hellenistic period it gained importance as a fortress by which the Macedonian rulers controlled central Greece. It was used by kings Antiochus III. of Syria (192) and Mithradates VI. of Pontus (88) as a base for invading Greece. Under Roman rule Chalcis retained a measure of commercial prosperity; since the 6th century A.D. it again served as a fortress for the protection of central Greece against northern invaders. ”
