The flushable toilet was invented in 1596 by Sir John Harrington. The godson of Queen Elizabeth I, Harrington built and installed his invention for the queen.
Harrington's design was the forerunner for the modern toilet with its flush valve and water wash-down system that helped empty and clean the bowl. Although he installed one at Richmond Palace, Queen Elizabeth I said it made too much noise and refused to use it.
It wasn't until the 1800s that people began to realize unsanitary conditions increased the spread of illnesses and diseases. This created a push to make affordable, flushable toilets for the general public.