A disparaging term dating back to the 12th century which refers to: 1. Unscrupulous feudal lords who amassed personal fortunes by using illegal and immoral business practices, such as illegally charging tolls to passing merchant ships.2. Modern-day businesspeople who allegedly engage in unethical business tactics and questionable stock market transactions to build large personal fortunes. Due to the robber barons' unethical business practices, such as the exploitation of labor, the general public typically regards these aggressive capitalists with disdain. However, some historians argue that the late-19th century entrepreneurs usually referred to as "robber barons" - including Andrew Carnegie and John D. Rockefeller - are responsible for building a large portion of the U.S.'s current economic clout, because of their large investments in burgeoning American industries. Many also went on to become high-profile philanthropists.