* 1680: Christiaan Huygens creates a gunpowder-powered engine. This is considered a very early precursor to the internal combustion engine.
* 1794: Robert Street designed and built the first internal combustion engine using hydrogen gas.
* 1860: Étienne Lenoir patented the first commercially successful internal combustion engine, which was a two-stroke engine that ran on coal gas.
* 1876: Nikolaus Otto developed a four-stroke engine that was more efficient than Lenoir's design.
* 1886: Karl Benz built the first practical gasoline-powered automobile, using an internal combustion engine of his own design.
Therefore, there isn't a single "invention date" for the internal combustion engine, but rather a series of advancements and breakthroughs that led to its modern form.