The centerpiece of today’s modern bathroom, the flush toilet has equal roots in ancient sanitation practices, Elizabethan politics and Industrial Revolution know-how.

Primitive latrines that utilized a constant stream of water to carry away waste date back at least 5,000 years, and early toilet systems were used by the several ancient civilizations, including the Romans and the Mohenjo-Dara and Harappa of the Indus Valley.

The first modern flushable toilet was described in 1596 by Sir John Harington, an English courtier and the godson of Queen Elizabeth I. Harington’s device called for a 2-foot-deep oval bowl waterproofed with pitch, resin and wax and fed by water from an upstairs cistern. Flushing Harington’s pot required 7.5 gallons of water—a veritable torrent in the era before indoor plumbing. Harington noted that when water was scarce, up to 20 people could use his commode between flushes.

Harington described his device in a satirical pamphlet entitled "A New Discourse on a Stale Subject, called the Metamorphosis of Ajax”—a pun on the term “a jakes,” which was a popular slang term for toilets. Although Harington installed a working model for Queen Elizabeth at Richmond Palace, it took several centuries—and the Industrial Revolution’s improvements in manufacturing and waste disposal—for the flush toilet to catch on.

In 1775 Scottish inventor Alexander Cumming was granted the first patent for a flush toilet. His greatest innovation was the S-shaped pipe below the bowl that used water to create a seal preventing sewer gas from entering through the toilet.

In the late-19th century, a London plumbing impresario named Thomas Crapper manufactured one of the first widely successful lines of flush toilets. Crapper did not invent the toilet, but he did develop the ballcock, an improved tank-filling mechanism still used in toilets today.

Crapper’s name would become synonymous with the devices he sold (although the English word “crap” predates him by centuries), thanks in part to American servicemen stationed overseas during World War I. These doughboys, unfamiliar with the relatively new-fangled invention, referred to the toilets as “crappers”—due to the Crapper brand’s ubiquity in England and France—and brought the term back home with them after the war.