Ruler for chief ruler, A.V. ( ἀρχισυνάγωγος, as in Acts 13:15); in for on, A.V. Crispus (a common Roman name) was one of the very few whom St. Paul himself baptized, probably on account of his important position as ruler of the synagogue, as we learn from 1 Corinthians 1:14.
With all his house (comp. Acts 16:33, Acts 16:34). Many of the Corinthians; i.e. of the Greeks and Romans, who composed the population of the city. It is seldom that we have the names of so many converts preserved as we have of this Achaian mission.
Besides Crispus and Gaius, we know of Epaenetus and Stephanas, who would seem to have been converted together (Romans 16:5; 1 Corinthians 16:15); and probably also Fortunatus and Achaicus (1 Corinthians 16:17).
Gains, from his name (Caius) and his salutation to the Church at Rome, was probably a Roman. Fortunatus and Achaicus also be-belonged, perhaps, to the Roman colony. Here too were many heathen converts (1 Corinthians 12:2), though mostly of the lower rank (1 Corinthians 1:26-29).