In the New Testament, these were tax collectors working for the Roman Empire. They were unpopular people, and Jewish publicans were despised by fellow Jews, who saw them as collaborators with the hated Romans.
Many of them were dishonest, scouring off extra funds for their own pockets. Though they were social outcasts, Jesus chose to socialize with them, and He even chose one (Matthew) as one of His twelve disciples. Zacchaeus was a publican whom Jesus visited and blessed (Luke 19).
Jesus also told a parable of a humble publican who could only pray, “God, be merciful to me a sinner!” (Luke 18:13).
Jesus’ compassionate outreach to publicans provoked criticism from the Jewish religious establishment.