Publicans at the time of Christ were basically tax collectors although they could also have roles in supplying the Roman military, managing port contracts, or overseeing building contracts.
Publicans at the time of Christ were basically tax collectors although they could also have roles in supplying the Roman military, managing port contracts, or overseeing building contracts. Publicans weren’t employees of Rome but contractors chosen from among upper class people (although not the ruling class).
Publicans were mostly known as tax collecting contractors in Galilee and Matthew filled that position in Capernaum. Publicans actually won their positions by bidding for them at auctions. The person would name the amount of the taxes he thought he could collect and then he would pay that amount to Rome. Rome treated the money as a loan and paid interest back to the publican. If the publican collected more than the original amount he got to keep it. There was a risk, though. If the publican collected less than he expected, they he had to pay the balance to Rome.
There were publicans that earned a lot of money this way. The Jews hated being occupied by the Romans, and they hated the tax collectors who worked for the Romans. Note that Matthew was already wealthy and although he was Jewish, had to be an upper class Roman citizen, like Paul.
Jesus looked upon Matthew and knew that he had a pure heart. He was absolutely fair in his dealings and never tried to tax the Jews to build his own wealth. When he invited Jesus to his house, he invited other publicans who were also able to feel the spirit when Jesus taught them.