Born in 1844 in Baden Muehlburg (now part of Karlsruhe), the son of an engine driver.
Educated at the Karlsruhe grammar school and the Karlsruhe Polytechnic. He worked for a number of different firms before founding his first company, supplying building materials, in 1871 with August Ritter.
Financial problems caused Benz to start work on a two-stroke engine, in the hope of finding a new income. He took out various patents on this in 1879. Benz found two new partners and started Benz & Co. in 1883 in Mannheim to produce industrial engines.
Benz then set to designing a "motor carriage", with an fourstroke engine. Benz designed not only his engine (958cc, 0.75hp), but the whole three wheel vehicle. On January 29 1886, he was granted a patent on it (DRP 37435) and in July he introduced the first automobile.
In 1903, Karl Benz retired from Benz & Cie, saving the firm from disaster as his ideas were already outdated by Daimler. But he was a member of the supervisory board of Daimler-Benz AG from 1926, when the company was formed, until his death.
He married Bertha Ringer in 1872, who had a significant role in his business, and had five children.