Okay, nobody knows who did it first. Ancient Egypt, Sumarians, or somebody else. The Chinese started with ornamental fish around 2000 years ago. Which is to stay they were breeding goldfish for looks. Thats about 2500 years after the Egyptians were keeping fish, which were sacred so they weren't food. About 200 years ago in Europe they started to understand what the fish needed to stay alive in a small captive environment, filtration and oxygen. The first public aquarium was opened in they mid 1800s. As soon as they figured how to make glass and silicone work they started pioneering aquariums as we know them. I don't know how old you are but some of us remember slate bottom tanks with metal frames. Thirty gallons was huge, and anything else went in a pond of your own making. This was also before water changes were believed in. I only caught the tail end of the hobby in that form. But old water was believe to be the only way to keep fish alive. Changing your water was feared. It has come far.