Karl Benz was born Karl Friedrich Michael Vaillant, on 25 November 1844 in Mühlburg, now a borough of Karlsruhe, Baden-Württemberg, which is part of modern Germany, to Josephine Vaillant and a locomotive driver, Johann Georg Benz, whom she married a few months later. According to German law, the child acquired the name “Benz” by legal marriage of his parents Benz and Vaillant. When he was two years old, his father died of pneumonia, and his name was changed to Karl Friedrich Benz in remembrance of his father.

Despite living in near poverty, his mother strove to give him a good education. Benz attended the local grammar school in Karlsruhe and was a prodigious student. In 1853, at the age of nine he started at the scientifically oriented Lyceum. Next he studied at the Poly-Technical University under the instruction of Ferdinand Redtenbacher.

Benz had originally focused his studies on locksmithing, but he eventually followed his father’s steps toward locomotive engineering. On 30 September 1860, at age 15, he passed the entrance exam for mechanical engineering at the University of Karlsruhe, which he subsequently attended. Benz graduated 9 July 1864 aged 19.

He then moved to Mannheim to work as a draftsman and designer in a scales factory. In 1868 he went to Pforzheim to work for a bridge building company Gebrüder Benckiser Eisenwerke und Maschinenfabrik. Finally, he went to Vienna for a short period to work at an iron construction company.

In 1871, at the age of twenty-seven, Karl Benz joined August Ritter in launching the Iron Foundry and Mechanical Workshop in Mannheim, later renamed Factory for Machines for Sheet-metal Working.

On 20 July 1872, Karl Benz and Bertha Ringer married. They had five children: Eugen (1873), Richard (1874), Clara (1877), Thilde (1882), and Ellen (1890).

Despite the business misfortunes, Karl Benz led in the development of new engines in the early factory he and his wife owned. To get more revenues, in 1878 he began to work on new patents. First, he concentrated all his efforts on creating a reliable petrol two-stroke engine. Benz finished his two-stroke engine on 31 December 1879, New Year’s Eve, and was granted a patent for it in 28 June 1880.

Problems arose again when the banks at Mannheim demanded that Bertha and Karl Benz’s enterprise be incorporated due to the high production costs it maintained. The Benzes were forced to improvise an association with photographer Emil Bühler and his brother (a cheese merchant), to get additional bank support. The company became the joint-stock company Gasmotoren Fabrik Mannheim in 1882.

After all the necessary incorporation agreements, Benz was unhappy because he was left with merely five percent of the shares and a modest position as director. Worst of all, his ideas weren’t considered when designing new products, so he withdrew from that corporation just one year later, in 1883.

Benz’s lifelong hobby brought him to a bicycle repair shop in Mannheim owned by Max Rose and Friedrich Wilhelm Eßlinger. In 1883, the three founded a new company producing industrial machines: Benz & Companie Rheinische Gasmotoren-Fabrik, usually referred to as Benz & Cie. Quickly growing to twenty-five employees, it soon began to produce static gas engines as well.

The success of the company gave Benz the opportunity to indulge in his old passion of designing a horseless carriage. Based on his experience with, and fondness for, bicycles, he used similar technology when he created an automobile. It featured wire wheels (unlike carriages’ wooden ones) with a four-stroke engine of his own design between the rear wheels, with a very advanced coil ignition and evaporative cooling rather than a radiator. Power was transmitted by means of two roller chains to the rear axle. Karl Benz finished his creation in 1885 and named it “Benz Patent Motorwagen”.

The Motorwagen was patented on 29 January 1886 as DRP-37435: “automobile fueled by gas”. The 1885 version was difficult to control, leading to a collision with a wall during a public demonstration. The first successful tests on public roads were carried out in the early summer of 1886. The next year Benz created the Motorwagen Model 2, which had several modifications, and in 1889, the definitive Model 3 with wooden wheels was introduced, showing at the Paris Expo the same year.

The great demand for static internal combustion engines forced Karl Benz to enlarge the factory in Mannheim, and in 1886 a new building located on Waldhofstrasse (operating until 1908) was added. Benz & Cie. had grown in the interim from 50 employees in 1889 to 430 in 1899.

The early 1888 version of the Motorwagen had only two gears and could not climb hills unaided. This limitation was rectified after Bertha Benz made her famous trip driving one of the vehicles a great distance and suggested to her husband the addition of a third gear for climbing hills. In the course of this trip she also invented brake pads.

Benz’s Model 3 made its wide-scale debut to the world in the 1889 World’s Fair in Paris; about twenty-five Motorwagens were built between 1886 and 1893.

The new directors recommended that Benz should create a less expensive automobile suitable for mass production. In 1893, Karl Benz created the Victoria, a two-passenger automobile with a 2.2 kW (3.0 hp) engine, which could reach the top speed of 18 km/h (11 mph) and had a pivotal front axle operated by a roller-chained tiller for steering. The model was successful with 85 units sold in 1893.

In 1895, Benz designed the first truck with an internal combustion engine in history. Benz also built the first motor buses in history in 1895, for the Netphener bus company.

In 1896, Karl Benz was granted a patent for his design of the first flat engine. It had horizontally opposed pistons, a design in which the corresponding pistons reach top dead centre simultaneously, thus balancing each other with respect to momentum. Flat engines with four or fewer cylinders are most commonly called boxer engines, boxermotor in German, and also are known as horizontally opposed engines. This design is still used by Porsche, Subaru, and some high performance engines used in racing cars. In motorcycles, the most famous boxer engine is found in BMW Motorrad, though the boxer engine design was used in many other models, including Victoria, Harley-Davidson XA, Zündapp, Wooler, Douglas Dragonfly, Ratier, Universal, IMZ-Ural, Dnepr, Gnome et Rhône, Chang Jiang, Marusho, and the Honda Gold Wing.

During the last years of the nineteenth century, Benz was the largest automobile company in the world with 572 units produced in 1899.

Because of its size, in 1899, Benz & Cie. became a joint-stock company with the arrival of Friedrich von Fischer and Julius Ganß, who came aboard as members of the Board of Management. Ganß worked in the commercialization department, which is somewhat similar to marketing in contemporary corporations.

Although Gottlieb Daimler died in March 1900—and there is no evidence that Benz and Daimler knew each other nor that they knew about each other’s early achievements—eventually, competition with Daimler Motoren Gesellschaft (DMG) in Stuttgart began to challenge the leadership of Benz & Cie. In October 1900, the main designer of DMG, Wilhelm Maybach, built the engine that would later be used in the Mercedes-35hp of 1902. The engine was built to the specifications of Emil Jellinek under a contract for him to purchase thirty-six vehicles with the engine, and for him to become a dealer of the special series. Jellinek stipulated the new engine be named Daimler-Mercedes (for his daughter). Maybach would quit DMG in 1907, but he designed the model and all of the important changes. After testing, the first was delivered to Jellinek on 22 December 1900. Jellinek continued to make suggestions for changes to the model and obtained good results racing the automobile in the next few years, encouraging DMG to engage in commercial production of automobiles, which they did in 1902.

Benz countered with Parsifil, introduced in 1903 with a vertical twin engine that achieved a top speed of 60 km/h (37 mph). Then, without consulting Benz, the other directors hired some French designers.

France was a country with an extensive automobile industry based on Maybach’s creations. Because of this action, after difficult discussions, Karl Benz announced his retirement from design management on 24 January 1903, although he remained as director on the Board of Management through its merger with DMG in 1926 and, remained on the board of the new Daimler-Benz corporation until his death in 1929.

Benz’s sons Eugen and Richard left Benz & Cie. in 1903, but Richard returned to the company in 1904 as the designer of passenger vehicles.

Karl Benz, Bertha Benz, and their son, Eugen, moved 10 kilometres (6.2 mi) east of Mannheim to live in nearby Ladenburg, and solely with their own capital, founded the private company, C. Benz Sons (German: Benz Söhne) in 1906, producing automobiles and gas engines. The latter type was replaced by petrol engines because of lack of demand.

In 1909, the Blitzen Benz was built in Mannheim by Benz & Cie. The bird-beaked vehicle had a 21.5-liter (1312ci), 150 kW (200 hp) engine, and on 9 November 1909 in the hands of Victor Hémery of France, the land speed racer at Brooklands, set a record of 226.91 km/h (141.94 mph), said to be “faster than any plane, train, or automobile” at the time, a record that was not exceeded for ten years by any other vehicle. It was transported to several countries, including the United States, to establish multiple records of this achievement.

In 1912, Karl Benz liquidated all of his shares in Benz Sons and left the family-held company in Ladenburg to Eugen and Richard, but he remained as a director of Benz & Cie.

During a birthday celebration for him in his home town of Karlsruhe on 25 November 1914, the seventy-year-old Karl Benz was awarded an honorary doctorate by his alma mater, the Karlsruhe University, thereby becoming—Dr. Ing. h. c. Karl Benz.

The German economic crisis worsened. In 1923 Benz & Cie. produced only 1,382 units in Mannheim, and DMG made only 1,020 in Stuttgart. The average cost of an automobile was 25 million marks because of rapid inflation. Negotiations between the two companies resumed and in 1924 they signed an “Agreement of Mutual Interest” valid until the year 2000. Both enterprises standardized design, production, purchasing, sales, and advertising—marketing their automobile models jointly—although keeping their respective brands.

On 28 June 1926, Benz & Cie. and DMG finally merged as the Daimler-Benz company, baptizing all of its automobiles, Mercedes-Benz, honoring the most important model of the DMG automobiles, the 1902 Mercedes 35 hp, along with the Benz name. The name of that DMG model had been selected after ten-year-old Mercédès Jellinek, the daughter of Emil Jellinek who had set the specifications for the new model. Between 1900 and 1909 he was a member of DMG’s board of management, however had resigned long before the merger.

Karl Benz was a member of the new Daimler-Benz board of management for the remainder of his life. A new logo was created in 1926, consisting of a three pointed star (representing Daimler’s motto: “engines for land, air, and water”) surrounded by traditional laurels from the Benz logo, and the brand of all of its automobiles was labeled Mercedes-Benz. Model names would follow the brand name in the same convention as today.

The next year, 1927, the number of units sold tripled to 7,918 and the diesel line was launched for truck production. In 1928, the Mercedes-Benz SSK was presented.

On 4 April 1929, Karl Benz died at home in Ladenburg at the age of eighty-four from a bronchial inflammation. Until her death on 5 May 1944, Bertha Benz continued to reside in their last home. Members of the family resided in the home for thirty more years. The Benz home now has been designated as historic and is used as a scientific meeting facility for a nonprofit foundation, the Gottlieb Daimler and Karl Benz Foundation, that honors both Bertha and Karl Benz for their roles in the history of automobiles.

He was inducted into the Automotive Hall of Fame in 1984 and the European Automotive Hall of Fame.

In 2008, the Bertha Benz Memorial Route was officially approved as a route of the industrial heritage of mankind, because it follows Bertha Benz’s tracks of the world’s first long-distance journey by automobile in 1888. The public can now follow the 194 km of signposted route from Mannheim via Heidelberg to Pforzheim (Black Forest) and back. The return trip – which didn’t go through Heidelberg – was along a different, slightly shorter route, as shown on the maps of the Bertha Benz Memorial Route.

In 2011, a dramatized television movie about the life of Karl and Bertha Benz was made named Carl & Bertha which premiered on 11 May and was aired by Das Erste on 23 May. A trailer of the movie and a “making of” special were released on YouTube.