In ancient Rome they didn't have a police force. What they had was essentially muscle for hire, mercenary bands paid by rich and powerful folks to do their bidd

In ancient Rome they didn't have a police force. What they had was essentially muscle for hire, mercenary bands paid by rich and powerful folks to do their bidding. As a regular person, the only thing that could have protected you from one of these groups was another such group. Same today with the licensing system.