Although held at a single location, the physical ownership of the Rupert Brooke collection is split into two parts. One part is held by King's College, Cambridge. The other is held by the Brooke Trustees, who have deposited the papers at King's College to provide public access. The collection has a complex administrative history. At Rupert Brooke's death, Mrs Mary Ruth Brooke, his mother, appointed Sir Edward Marsh literary executor. However, at her death in 1930 a group of literary trustees were appointed that did not include Eddie Marsh, for in the years between Brooke's death and 1930 Mrs Brooke and Sir Edward had had many disagreements over the publishing of her son's work and the content of Marsh's 'Memoir'. The newly appointed literary trustees, Geoffrey Keynes (the most active), Walter de la Mare, Dudley Ward and John Tresidder Sheppard, were charged, according to the terms of Mrs Brooke's will, with overseeing the sale of Brooke's books and the disposition of such of his manuscripts as were not in the hands of Eddie Marsh in King's College Library. In the event, Marsh relinquished his life interest in certain manuscripts bequeathed to him by Mrs Brooke and significant bodies of material were transferred to King's during 1931 from both him and the literary executors. In the hands of Marsh and Keynes, a substantial amount of poetry and letters subsequently transferred were bound. The papers transferred also included transcripts of Brooke poems and letters collected by both men in preparation for publication.

The 'collection', therefore, must be seen as exactly that: the accumulations of several interested individuals, Marsh, Mrs Brooke and Keynes, alongside the papers left by the poet at his death, his 'archive' proper. Subsequent transfers were made by the Trustees on several occasions, including a substantial additional body of Keynes's correspondence in 1980. Material was also presented to the library from other interested individuals, among them Hugh Dalton in 1962. The manuscript material held by John Schroder was purchased in 2015 and is catalogued here in section RCB/S.