The Grenville collection consists of 131 slip cases and two loose bundles of maps and charts. The slip cases are in mock book form, covered in green leather, and inside the maps have been carefully dissected, mounted on linen and edged with coloured silk ribbon. The spines of the cases are numbered and named by geographic area, with occasional mention of individual cartographers as well. The collection covers the world with the main emphasis on Europe and for the most part consists of maps published in the latter half of the eighteenth century. It would appear that they were mostly assembled within the short space of time during which their collector: William Wyndham Grenville (1759-1834), was foreign minister between 1791 and 1801. They are an interesting reflection, therefore, on the cartographic material available to an English politician at the close of the eighteenth century. It appears that the bulk of the map collection was assembled by Grenville during his early years as Foreign Minister. It represents his desire to bring himself abreast of current knowledge of the world and especially to gain a working knowledge of European affairs at the time. The collection is an interesting vehicle therefore by which a contemporary view of the world as it appeared to an English politician at the end of the eighteenth century can be gained. As Foreign Secretary Grenville needed to know aspects of military policy and there is a significant collection of maps relating to the war campaigns of eighteenth-century Europe.

Grenville was a member of a prominent Whig family who had been at the forefront of the political scene for much of the eighteenth century, indeed his father had been Prime Minister from 1763 to 1765. An important family tie was to have a significant influence on Grenville's career, that of his cousin, William Pitt the younger (1759-1806). Under Pitt's Ministry Grenville was advanced to the post of Paymaster General in 1783. This was one of the most prestigious posts of government and was usually reserved for those who had already served in other, more junior posts. In 1784, he was made one of the commissioners of the newly created Board of Control and in September 1786 was appointed Vice President of the Committee of Trade. He gained a seat in the House of Lords in 1790 when he was created Baron Grenville of Wotton-under-Bernewood, although not before he had been made Speaker of the Commons at the early age of thirty. He had in fact only held the post very briefly before being made Secretary of State for the Home Department towards the end of 1789. In 1791, Grenville was appointed Secretary of State for Foreign Affairs. Grenville succeeded William Pitt as Whig Prime Minister in 1806 and led the 'All the Talents' coalition government for a year until 1807. His ministry was largely unsuccessful, although just before his resignation, he did secure the abolition of slavery. He was repaced by the Tories under the Duke of Portland and remained in political opposition until his retirement in 1823. Grenville subsequently suffered a long period of ill-health until his death in 1834.