The British Library is a research library in London that is the national library of the United Kingdom. It is one of the largest libraries in the world. It is estimated to contain between 170 and 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 United Kingdom. The Library is a non-departmental public body sponsored by the Department for Culture, Media and Sport.
https://en.wikipedia.org/wiki/British_Library