The history of toilets dates back to ancient civilizations, where early forms of sanitation were developed. The Indus Valley Civilization (around 2500 BCE) had sophisticated drainage systems and public toilets. In ancient Rome, public latrines were common, featuring long benches with holes, allowing multiple users at once. During the Middle Ages, sanitation declined, and waste disposal became a problem in many cities. The modern flush toilet was invented in the late 16th century by Sir John Harington, but it wasn't until the 19th century that plumbing systems improved, leading to widespread use of indoor toilets.