Cassiano dal Pozzo was famous in his own lifetime, but is now known to few, except a select group of scholars. Diplomat, humanist, patron of the arts and collector, dal Pozzo was secretary to Pope Urban VIII’s cardinal nephew, Francesco Barberini, and the creator of the famous “Museo cartaceo” (paper museum), a collection of 20,000 works on paper, some by leading artists of the day, to form a kind of visual encyclopaedia of natural history specimens and antiquities. Now in his home town, an international loan exhibition (until 16 March) brings together a number of works to conjure up the spirit of his collection. Lenders include the Budapest Museum, the Prado, the Uffizi, and the Kunsthistorisches Museum, along with a large number of private individuals and collections. No less than eight works by Poussin will join those by Bernini, da Cortona, Romanelli, Turchi, Vouet, Van Dyck, plus a previously unpublished portrait of Artemisia Gentileschi painted in 1622 for dal Pozzo by Simon Vouet. A series of paintings has been chosen to illustrate Cassiano’s social circles and connections. Certain artists whose works were known to have been in the collection, such as Claude, Sacchi and Lemaire, but which are not available for this exhibition, are represented by similar pieces. The paper museum is epitomised by the copy of Leonardo’s treatise on painting made at Cassiano’s request by Poussin with with 27 illustrations.