Caesar III is a 1998 Windows city building game, so it’s like SimCity, but more fast paced, focused on efficiency, and set in Ancient Rome. You can get it from Steam or GOG. But the game is old, and clearly aged software and gameplay wise.
Then someone created a reimplementation named Julius project, adding some QoL improvement and compatibility with other OSes. And then someone else forked the project and added gameplay changes as well, incorporating features from later games.