Although widely and erroneously credited to 19th-century British plumber Thomas Crapper, the modern flush toilet was actually invented in 1596 by Sir John Harrington. His treatise, titled "A New Discourse of a Stale Subject, Called the Metamorphosis of Ajax," described an early type of flush toilet.
The S-trap, a critical improvement to Harrington's design, was developed in 1775 by Alexander Cumming. This innovation used standing water to seal off the toilet bowl from the sewer main below it, preventing odors from emanating forth.
Primitive Neolithic flush toilets have been found in ancient village ruins in Britain. A river and connected drainage system swept waste away from habitable areas. The Indus Valley civilization of ancient India, the Minoan civilization and the Roman Empire used forms of hydraulic toilets for centuries prior to Sir Harrington's invention.