New research suggests Stonehenge was used as a burial ground for about 500 years; potentially from the site's inception. From the article:
Archaeologists have said the cremation burials found at the site might represent a single elite family and its descendents - perhaps a ruling dynasty.
One clue to this idea is that there are few burials in the earliest phase, but that the number grows larger in later centuries, as offspring multiplied.
Under the traditional view, cremation burials were dug at the site between 2,700 BC and 2,600 BC, about a century before the large stones - known as sarsens - were put in place.
BBC: "Stonehenge 'a long-term cemetery'".