Prehistoric period: Traders
Since a "businessman" can mean anyone in industry or commerce, businessmen have existed as long as industry and commerce have existed. "Commerce" can simply mean "trade", and trade has existed through all of recorded history. The first businessmen in human history were traders or merchants.
Medieval period: Rise of the merchant class
Merchants emerged as a "class" in medieval Italy. Between 1300 and 1500, modern accounting, the bill of exchange, and limited liability were invented, and thus the world saw "the first true bankers", who are certainly businessmen.
Around the same time, Europe saw the "emergence of rich merchants." This "rise of the merchant class" came as Europe "needed a middleman" for the first time, and these "burghers" or "bourgeois" were the people who played this role.
Renaissance to Enlightenment: Rise of the capitalist
Europe became the dominant global commercial power in the 16th century, and as Europeans developed new tools for business, new types of business people began to use those tools. In this period, Europe developed and used paper money, cheques, and joint-stock companies (and their shares of stock). Developments in actuarial science led to insurance. Together, these new tools were used by a new kind of businessman, the capitalist. These people owned or financed businesses as bankers, but they were not merchants of goods. These capitalists were a major force in the Industrial Revolution...
Modern period: Rise of the manager
The newest kind of businessperson is the manager. One of the first true managers was Robert Owen (1771–1858), an industrialist in Scotland. He studied the "problems of productivity and motivation", and was followed by Frederick Winslow Taylor, who was the first person who studied work. After World War I, management became popular due to the example of Herbert Hoover and the Harvard Business School, which offered degrees in business administration (management).