The Library began with the founding of Trinity College in 1592. In 1661, Henry Jones presented it with the Book of Kells, its most famous manuscript. James Ussher (1625–56), Archbishop of Armagh, whose most important works were "Veterum Epistolarum Hibernicarum Sylloge" (1632) and "Brittanicarum Ecclesiarum Antiquitates" (1639), left his valuable library, comprising several thousand printed books and manuscripts, to the Library. His complete works were published by the Library in twenty-four volumes.[3]
In 1801, the Library was given legal deposit rights, making it the only library in Ireland to have such rights for the United Kingdom.[3] Starting at 4 pm on Saturday 29 November 2009, the Trinity Students' Union organized a 24-hour sit-in in protest at a reduced book-buying budget, lack of access to books on Sundays, and a proposed reduction of counter services.[4]