But, the invaders came into a countries that had given up on human sacrifices. Even Ireland had already embraced christianity: when the Germanic invasion of Britain cut it off from the continent, it wrote the book of Kells and sent missions to Scotland.

Actually, there's some very good stuff on the origins of Halloween at http://www.geocities.com/Athens/Delphi/6696/hallows.htm. It's solidly researched and it debunks some scare literature about the festival.

Charles