The majority of wealth in the hands of the ruling class, owning one's own business was a rare sight. The old-world entrepreneurs mostly consisted of merchants and craftsmen. Plenty of merchants created their own business, but a lot of the time the business and connections were handed down generation to generation. Skilled craftsmanship was another family affair, but anyone with the right connections that was lucky enough to land an apprenticeship and succeed at it we're able to climb the economic ladder a little higher.
Merchants started to take over be more prominent as the world market grew because of exploration and sailing and shipping became easier. It wasn't until the industrial age when the big business was back in a central location. Inventors were a large part of the entrepreneurial field. Using new technology, manufacturing, transportation and ingenuity, inventors dominated the industrial age.
The 20th century was the home of the media kings. Radio, television and film blew up creating new industries across the globe. Finally, the our current Information Age came upon us in the 80's. Since then moguls have been materialized from one single good idea worth billions upon billions of dollars. What's next for the entrepreneur? We'll have to wait and see.