While the Celts did not practice the art of mummification purposefully, some bodies have been preserved in peat bogs with remarkable detail. The May/June 2010 issue of Archaeology magazine has a nice article on some of the more sensational bog body finds and how they have been interpreted (usually incorrectly) over time. The last page of the article discusses two famous Irish peat bog bodies named Clonycavan Man and Old Croghan Man. These bodies date to between 400 and 200 BC, over 800 years before our period, but still very interesting. I will attach a scan of the relevant page to this post.