According to
Wikipedia, cremation dates back at least 20,000 years ago in Australia, while in Europe, there is evidence of cremation dating to around 2,000 B.C. Cremation was common in Ancient Greece and Rome, and it remains a standard practice in India. The practice of cremation faded in Europe by the fifth century and during the Middle Ages, it was primarily used in the punishment of heretics or in response to the fear of contagious diseases. Today, cremation is preferred by more and more people around the world.
The traditional cremation process consists of reducing a body at very high temperatures until it is nothing but brittle, calcified bones. These are then processed into what we commonly call ashes. Returned to the family in a temporary urn (or a more personal urn selected by the family), these ashes can be kept, buried, or scattered. Some families even choose to place a loved one's cremated remains in a hand-crafted piece of cremation art.
Author Michelle Kim, in How Cremation Works, details the cremation process: "In modern crematories, the body is stored in a cool, temperature-controlled room until it's approved for cremation. The body is prepared by removing pacemakers, prostheses and silicone implants. The body is then put into a container or casket made out of flammable materials such as plywood, pine or cardboard."
The container is placed in the retort or cremating chamber. It takes anywhere from two to three hours to reduce an average adult to ash. When the cremated remains are cooled, they are processed to a uniformly-sized pebble-like substance and placed in an urn. The funeral director then returns the cremated remains to the family.