Historians know about the importance of private libraries to the early Enlightenment and by extension the entire age, but they know little about exactly what happened to them after 1750 and how what existed connected to collectors, collections, the constructed environment encasing them, and consumers. Professor Hancock will talk about the important private collection of books and manuscripts assembled by William Petty-Fitzmaurice, 2nd Earl of Shelburne and 1st Marquis of Lansdowne (1737-1805), Britain’s first Irish-born prime minister, and housed at his palace in London. He will examine the design, decoration and furnishing of a space to house them in, their acquisition, use and disposition between 1761 and 1805, and the tastes and thoughts they reflected. A large private library informed by universal principles like Lansdowne's was one of the prime movers of the late Enlightenment, domesticating and rendering practical that movement and, at the same time, playing an ambiguous, yet undeniably critical role as an instrument of incipient Revolution.