Prior to 1860
Model of the Barsanti-Matteucci engine (1853) in the Osservatorio Ximeniano in Florence
5th century: Roman engineers documented several crankshaft-connecting rod machines used for their sawmills.
17th century: Christiaan Huygens designs gunpowder to drive water pumps, to supply 3000 cubic meters of water/day for the Versailles palace gardens, essentially creating the first idea of a rudimentary internal combustion piston engine.
1780s: Alessandro Volta built a toy electric pistol in which an electric spark exploded a mixture of air and hydrogen, firing a cork from the end of the gun.
1791: John Barber receives British patent #1833 for A Method for Rising Inflammable Air for the Purposes of Producing Motion and Facilitating Metallurgical Operations. In it he describes a turbine.
1794: Robert Street built a compressionless engine whose principle of operation would dominate for nearly a century.
1798: Tippu Sultan, the ruler of the city-state of Mysore in India, uses the first iron rockets against the British Army.
1807: Nicéphore Niépce installed his 'moss, coal-dust and resin' fueled Pyréolophore internal combustion engine in a boat and powered up the river Saône in France. A patent was subsequently granted by Emperor Napoleon Bonaparte on 20 July 1807.
1807: Swiss engineer François Isaac de Rivaz built an internal combustion engine powered by a hydrogen and oxygen mixture, and ignited by electric spark. (See 1780s: Alessandro Volta above.) 
1823: Samuel Brown patented the first internal combustion engine to be applied industrially. It was compressionless and based on what Hardenberg calls the "Leonardo cycle," which, as the name implies, was already out of date at that time.
1824: French physicist Sadi Carnot established the thermodynamic theory of idealized heat engines. This scientifically established the need for compression to increase the difference between the upper and lower working temperatures.
1826 April 1: American Samuel Morey received a patent for a compressionless "Gas or Vapor Engine."
1833: Lemuel Wellman Wright, UK patent 6525, table-type gas engine. Double acting gas engine, first record of water jacketed cylinder.
1838: A patent was granted to William Barnett (English). According to Dugald Clerk, this was the first recorded use of in-cylinder compression.
1854-57: Eugenio Barsanti & Felice Matteucci invented an engine that was possibly the first 4-cycle engine, but the patent was lost.[note 1]
Early internal combustion engines were used to power farm equipment similar to these models.
This internal combustion engine was an integral aspect of the patent for the first patented automobile, made by Karl Benz on January 29, 1886
1856: in Florence at Fonderia del Pignone (now Nuovo Pignone, later a subsidiary of General Electric), Pietro Benini realized a working prototype of the Italian engine supplying 5 HP. In subsequent years he developed more powerful engines—with one or two pistons—which served as steady power sources, replacing steam engines.
1857: Eugenio Barsanti & Felice Matteucci describe the principles of the free piston engine where the vacuum after the explosion allows atmospheric pressure to deliver the power stroke (British patent No 1625). Otto and Langen were the first to make a marketable engine based on this concept 10 years later.