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 officially part of the Duchy of Normandy and as such, Queen Elizabeth II often toasted as Duke of Normandy. However, pursuant to the Treaty of Paris (1295) and Salic Law, she technically is not the Duke and instead governs in her right as Queen.
The islands' governments are responsible to The Queen in Council (where she has traditionally been advised by the Home Secretary) until 2001, when responsibility for the Channel Islands and the Isle of Man passed to the Lord Chancellor's Department. In 2003, this was replaced by a Department of Constitutional Affairs. Neither Island has representation in the UK Parliament, and Acts of that Parliament are only extended to the Islands, by Order in Council, after local consultation. Their citizens hold British passports, which bear the words 'British Islands', as opposed to 'United Kingdom'. Under the Interpretation Act 1978, they are deemed to be part of the British Islands, not to be confused with the British Isles, of which they are also historically considered a part.
The inhabited islands of the Channel Isles are Jersey, Guernsey, Alderney, Sark, Herm, (the main islands) Jethou, Brecqhou (Brechou) and Lihou. All of these except Jersey are in the Bailiwick of Guernsey. (There is another small inhabited island Chausey, south of Jersey. Because it is owned by France it is very little known, even to Channel Islanders.)
They were originally part of the lands in France owned by the Duke of Normandy. In 1066 the Duke William the Conqueror 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 Islands remain.
During the Second World War they were occupied by Germany.
Victor_Hugo spent many years in exile on Guernsey and wrote Les miserables there. Guernsey is also the setting of Hugo's later novel, Les travailleurs de la mer (The Toilers of the Sea).