The British Library

The British Library is the national library of the United Kingdom and is one of the largest libraries in the world. It is estimated to contain between 170–200 million items from many countries. As a legal deposit library, the British Library receives copies of all books produced in the United Kingdom and Ireland, including a significant proportion of overseas titles distributed in the UK. The Library is a non-departmental public body sponsored by the Department for Digital, Culture, Media and Sport. (Wikipedia)

For more information, visit The British Library's website.