from
Easton's 1897 Bible Dictionary
Sosthenes
safe in strength, the chief ruler of the synagogue at Corinth,
who was seized and beaten by the mob in the presence of Gallio,
the Roman governor, when he refused to proceed against Paul at
the instigation of the Jews (Acts 18:12-17). The motives of this
assault against Sosthenes are not recorded, nor is it mentioned
whether it was made by Greeks or Romans. Some identify him, but
without sufficient grounds, with one whom Paul calls "Sosthenes
our brother," a convert to the faith (1 Cor. 1:1).