A national library is a library specifically established by the government of a country to serve as the preeminent repository of information for that country. Unlike public libraries, these rarely allow citizens to borrow books. Often, they include numerous rare, valuable, or significant works. A National Library is that library which has the duty of collecting and preserving the literature of the nation within and outside the country, Thus, National Library are those libraries whose community is the nation at large. Examples include; The British Library, The Bibliothèque Nationale In Paris.
There are wider definitions of a national library, putting less emphasis to the repository character.
National libraries are usually notable for their size, compared to that of other libraries in the same country. Some states which are not independent, but who wish to preserve their particular culture, have established a national library with all the attributes of such institutions, such as legal deposit.
Many national libraries cooperate within the National Libraries Section of the International Federation of Library Associations and Institutions (IFLA) to discuss their common tasks, define and promote common standards and carry out projects helping them to fulfill their duties. National libraries of Europe participate in The European Library. This is a service of The Conference of European National Librarians (CENL).
The first national libraries had their origins in the royal collections of the sovereign or some other supreme body of the state.
One of the first plans for a national library was devised by the Welsh mathematician John Dee, who in 1556 presented Mary I of England with a visionary plan for the preservation of old books, manuscripts and records and the founding of a national library, but his proposal was not taken up.
In England, Sir Richard Bentley's Proposal for Building a Royal Library published in 1694 stimulated renewed interest in the subject. Sir Robert Cotton, 1st Baronet, of Connington, a wealthy antiquarian, amassed the richest private collection of manuscripts in the world at the time and founded the Cotton Library. After the Dissolution of the Monasteries, many priceless and ancient manuscripts that had belonged to the monastic libraries began to be disseminated among various owners, many of whom were unaware of the cultural value of the manuscripts. Sir Robert's genius was in finding, purchasing and preserving these ancient documents. After his death his grandson donated the library to the nation as its first national library. This transfer established the formation of the British Library.