Well the Barbary slave trade existed. People were stolen from Britain, France, Spain, Italy, Portugal even Iceland and taken to North Africa as slaves.

They reckon between 16th and 18th centuries 1.25 million white Europeans were taken in to slavery.

There's a great book out there written by a boy who was kidnapped from his village in England and taken as a slave to Morocco where he witnessed all sorts of torture (the King was partial to selecting his favourite boy slaves, hanging them upside down and skinning them alive or sawing them in half.) He managed to escape and made his way home and wrote the book, I can't for the life of me remember what it's called.

Slavery was not legal in England. It was found to be so in a number of famous court cases.

By "not legal," it was not legal for a man to be a slave in England. If a slave landed in England he or she became free. It was not illegal to own slaves (though they would become free if brought to England).

The first court case was "Smith v Gould" in 1701. Sir John Holt, Lord Chief Justice of England ruled, "No man can have property in another. There is no such thing as a slave by the law of England."

In 1705 in "Smith v Brown and Cooper", Chief Justice Holt re-iterated the same ruling, "As soon as a Negro comes into England he becomes free. One may be a villein in England, but not a slave".

Obviously, there were still some slave owners who brought their slaves into England and tried to get away with it, because there were several other famous court cases: In 1762, in "Shanley v Harvey", Lord Henley ruled, "As soon as a man sets foot on English ground, he is free."

In 1772 "Somersett's Case" again held that the condition of slavery did not exist under English law, and that slaves who arrived in England or Wales were free.

Slavery obviously was legal in many parts of the British Colonies. Britain banned the slave trade in 1807, and abolished slavery throughout the British Empire in 1833.

Source: http://www.anti-slaverysociety.addr.com/huk-slavery.htm

The term "slave" was not used in England at this time, but most people in England were not free at some level. Indentured servitude was common, the hierarchy was real and respected by them and anyone who wasn't a noble person was born into dependence on these nobles for land, food, shelter, jobs ect..Slavery wasn't addressed because it was pretty much the basis for society, just called it a different name. In 18th century America, only about 1in 5 people were actually "free". Gordon wood discusses this in "the radicalism of the American revolution. Not too sure about the rest of Europe though.