From goeurope.about.com, brought to you via googling “halloween in Europe”:
Question: Do they celebrate Halloween in Europe?
Answer: Why yes, they do. In fact, the whole Halloween thing seems to have be the results of combining the ancient Roman Feralia, commemorating the passing of the dead, with the Celtic Samhain. It seems to have passed from Europe to the US with Irish immigrants…
Halloween didn’t take its present form until All Saints Day was declared by Pope Gregory IV to replace the pagan festival. The night before became All Hallows Eve and people went door to door begging for food (or soul cakes) to feed the poor. Of course, things were tweaked a bit during the time between then and now…