It’s what you sleep on every night, but do you know the history behind your mattress? The oldest known mattress dates back 77,000 years ago and was discovered in the Sibudu Cave in KwaZulu-Natal in Africa. The mattress was composed of layers of reeds and rushes and was about 22 square feet in size – large enough to fit an entire family. Other ancient mattresses include ancient Egyptian wool cushion mattresses set on raised wooden beds and ancient Persian waterbeds made from goatskins filled with water that are thought to have been used to comfort the sick or elderly. Around 1000 BCE, the ancient Romans pioneered mattresses stuffed with feathers or straw (however, less fortunate citizens slept on simple mats). The basic design of the mattress didn’t change much from the Roman version until the mid-18th century, when mattresses started to be filled with coconut fibers, cotton, wool, or horsehair instead of common down or hay. Then in 1869, Timothy Rose and Platt S. Buell patented a bed spring in the US, creating the first innerspring mattress. (However, it took about 60 years to catch on!) The modern waterbed was introduced in 1968 by Charles Hall, and the first successful memory foam mattress debuted in 1991. Since then, various memory foam mattresses based on NASA’s 1966 invention of memory foam (which was originally created for use in airplane seats) have hit the market and now command a significant share of it.