A Frenchman, Etienne Lenoir, made the first commercially successful internal-combustion engine in 1860. It ran on coal gas, but worked on a cycle of operations, which did not include compression of the gas before ignition: as a result it was not very efficient. In spite of this it was in some respects superior to small steam engines of the time, and a great many were sold and did useful work driving machinery in factories. In 1862 Lenoir made a 'horseless-carriage' powered by his engine and possibly drove it on the roads, but he lost interest in this venture and nothing came of it. In fact, a method of carrying out the cycle of operations using compression of the gas, was described in a patent dated 16 January 1862 taken out by a French civil servant, M. Beau de Rochas. Since he did not have the means to develop the patent himself, the patentee offered it to Lenoir who, failing to realize its importance, turned it down.

However, in Germany, Dr N. A. Otto started the manufacture of gas engines around 1866. Although the first Otto engines were extremely noisy, they were quite effective. Around 1875 Otto took out a patent describing a method of carrying out the cycle of operations, which was in fact identical to that of Beau de Rochas' thirteen years earlier (It is however, most unlikely that Otto had heard of the Frenchman, or his patent). Otto's new engine was an immediate success. It was more efficient than Lenoir's and was very quiet, a characteristic which led to its being named 'Otto's silent gas engine'.

Lenoir, realizing his mistake, began to manufacture engines working on the same principle. Otto, of course, sued him for infringing his patent rights, but Lenoir had no difficulty in proving that his engines were made under the earlier patent of Beau de Rochas, which had by now lapsed. The court proceedings at last brought poor Beau de Rochas the fame he deserved, and he was awarded a sum of money by the Academy of Sciences in Paris in recognition of his invention. Even so, the method of operation, which was the first to describe, and which is the one used in most modern engines, was for many years (and sometimes still is) known as the Otto cycle.