The Channel Islands (or Channel Isles) are a group of islands off the coast of Normandy, France. Politically, they are divided between the Bailiwick of Guernsey and the Bailiwick of Jersey, both of which are British crown dependencies, but not part of the United Kingdom. They are conventionally considered part of the British Isles, although the reasons for this are more political than geographical.
They were originally part of the lands in France owned by the Duke of Normandy. In 1066 he invaded and conquered England, becoming the English monarch. Over the years, the rest of the monarch's lands in France were lost and now only the Channel Isles remain.