The library grew richer and larger and became the treasure-island under the direct patronage of Maharaja of Cooch Behar who sanctioned Rs.2,000 as annual grant for the purchase of books. Different punthis, manuscripts and rare documents of Raj-Darawabar  or royal-court were transferred to this library for public benefit. J.W.Troten in his book India under Victoria speaks of this library, “the little State of Cooch Behar on Assam border could be act of a library richer than any to be found in Bengal out side Calcutta”.

The Library became the storehouse of important documents, reports, journals and rare manuscripts. Most of rare books and documents are century’s old. It became a treasure of the cultural heritage of Cooch Behar Kingdom.

Just on the eve of merger of Cooch Behr State with the Indian Union, the Library was run by five employees including a Librarian of gazetted rank. The library then was under the Director Control of Minister In-charge of State Council. After the merger with the Union Govt., the library shifted under the control of the District Magistrate and the Government sanctioned only one Librarian and a peon [vide order no.-985-Edm(d)].

In a joint meeting with the prominent citizens of the Cooch Behar town on 13-NOV-1967 in the chamber of the Deputy Commissioner (Cooch Behar) it was unanimously resolved to amalgamate the State Library with the District Library, Cooch Behr. The District Library of Cooch Behar was established in the year 1957 under the sponsored Library scheme. According to the above resolution in the year 1968, the then Deputy Commissioner, Sri Bhaskar Ghosh, I.A.S., on the plea of saving the library sent a proposal of amalgamation with the District Library to the D.P.I. , West Bengal.

On the basis of his proposal government accepted the merger and renamed the Library as “North Bengal State Library” [vide G.O.No.,114-Edn(SE)].

The Library’s present collections. :  70,000 books

Descriptive Catalogue of Bengali Manuscripts