The site of Trinity College Dublin began its institutional life not as a place of secular learning but as an Augustinian priory, All Hallows, and the transition from monastic to academic use shaped everything that followed, including the collections that would eventually define the college's reputation across Europe.

In 1592 the mayor of Dublin granted the site of All Hallows to Adam Loftus, Archbishop of Dublin and Provost of the newly founded Queen Elizabeth's College of the Holy and Undivided Trinity. The college that took root on that repurposed ecclesiastical ground would, within a few decades, become the custodian of one of the most significant private libraries in early modern Ireland. James Ussher, who served as Archbishop of Armagh from 1625 to 1656, was a scholar of considerable output; his "Veterum Epistolarum Hibernicarum Sylloge", published in 1632, and "Brittanicarum Ecclesiarum Antiquitates", which appeared in 1639, were among his most important contributions to ecclesiastical history. On his death, Ussher left his entire library, comprising several thousand printed books and manuscripts, to Trinity College. The college later published his complete works in twenty-four volumes. By the 1700s, the area to the north-east of the main quadrangle had been reorganised around what became known as Library Square, reflecting just how central the accumulation and housing of books had become to the college's physical and intellectual identity.

Library Square sits within the main campus and is accessible through the front gate on College Green. The square itself is easy to overlook as a distinct space, since it blends into the broader flow of the campus, but knowing that it was deliberately laid out around the library building in the eighteenth century gives it a different quality when you pause there. The Long Room, the barrel-vaulted upper chamber of the Old Library, houses a portion of the Ussher collection alongside other early manuscripts, and is open to the public as part of a ticketed exhibition. Those with a particular interest in the ecclesiastical and manuscript history of the site will find the collections and their provenance, traced back through Ussher's bequest and the original Augustinian ground, a more layered story than the building's exterior suggests.