Robert Bosch was born in Southern Germany, September 1861, 11th of 12 children. His auspicious 1876 graduation from a secondary-technical Realschule in the city of Ulm marks a beginning in industry that would last almost 70 years.

After working for seven years at several companies, including Edison in New York and in the UK at Siemens, Bosch opened his own business, which he called a workshop for precision mechanics and electrical engineering. At first, Bosch accepted orders for all kinds of jobs. Among other things, he made cigar cutters, repaired signal horns, and even made house calls on his bicycle for installation work. However, Bosch's breakthrough came in 1897.

At the turn of the century, gasoline-powered combustion engines were still in their infancy. To spark off powering fuel explosions, three different ignition systems were used, but all had flaws. Battery ignition systems (which now power every passenger vehicle on the road) weren't yet rechargeable and had limited life. Resistor glow-tube ignitions were a fire hazard. Magnet-based ignitions relied on engine speed for power, so required an auxiliary ignition for starting. The most common auxiliary ignition, used in the Model T, was a fragile buzzer, prone to breakdown because voltages discharged by arcing across its working contact points — oxidizing and welding them in the process.

Deutz AG (established by engine inventor Nicolaus Otto and now known for air-cooled engines) manufactured an alternative magneto ignition device for stationary engines. Bosch customized one for a customer, and saw that it wasn't suitable for use on jarred moving engines, saying, “No technically effective machine could be built with 12 fragile magnets.”

Even so, Bosch knew the ignition device showed promise, so he tinkered with it. He strengthened it with more robust U-shaped magnets, pole shoes, and base and side plates. Then he tasked his factory manager, Arnold Zähringer, with increasing its sparking rate so it would function in the faster-firing engines of moving vehicles. (Zähringer's solution was to immobilize the armature and add a faster-flying metal sleeve around it to move through the plug's magnetic field.) “Whether at 100 or 600 ignitions a min., the ignition still works without skipping a beat,” Bosch bragged.

But one problem prevented mass production of the design: Its complicated break-spark rodding (which protrudes into the combustion chamber) had to be customized for every engine. So in 1901 Bosch tasked his development head, Gottlob Honold, with replacing it. Honold developed a simple system of two coils for creating the plug's high-voltage sparks. Many designers had toyed with two-electrode designs, but he included heat-resisting alloy electrodes and an insulated ceramic plug body that withstood the intense heat of sparking.

The perfected plug design was immediately applied to automobiles, at higher voltages, and quickly eliminated what Carl Benz considered the trickiest problem in automaking.

As his business grew far beyond the magneto, Bosch introduced one of Germany's first eight-hour working days and occupational training for associates — earning him the nickname “Red Bosch” with his fellow industrialists. About the company's healthy salaries Bosch said, “I don't pay good wages because I have a lot of money; I have a lot of money because I pay good wages.”

Antiwar for humanitarian and pragmatic reasons, Bosch donated company profits from World War I armaments contracts — millions of German marks — to charity. When war again threatened in the 1930s, Bosch rallied for peace and a Europe without customs barriers. Later, he established a repair shop in Stuttgart staffed by persecuted groups, to protect them from deportation.

Before he died in March 1942, Bosch stipulated that company earnings be allocated to charitable causes, so profit from Robert Bosch GmbH still benefits the nonprofit Robert Bosch Foundation. The company's industrial branch in the U.S., Bosch Rexroth Corp., with headquarters in Hoffman Estates, Ill., makes industrial technologies for mobile hydraulics and automated machines.