The Liber Boonen is a manuscript History of Leuven, its antiquities and ceremonies, written by William Boonen, a Clerk of the City Registry, in 1593/1594. It includes a full description of the city’s famous ommegang or procession, in honour of its patroness the Blessed Virgin Mary, whose statue as Sedes Sapientiae, ‘Seat of Wisdom’, is featured on the seal of the University. This statue was paraded annually from its home in St Peter’s Cathedral on the first Sunday in September (contiguous to the Feast of the Nativity of the Virgin Mary on 8 September), a procession associated with a popular Fair which bought revenue to the city in tolls and trade.

	Boonen was not only a dedicated and knowledgeable historian, who made full use of the materials available to him in the City archives, but a talented amateur artist. His History features a lively visual record of the procession, its marching craftsmen and shooters’ guilds, dignitaries from the Church, the religious orders and the University, its elaborate pageant-waggons, its giants, dragons, and the ambachtsvrouwen, the 38 heroines of the Old Testament typologically prefiguring the Blessed Virgin, who were the trades and crafts guilds’ contribution to the procession.
Marching among the civic officials are the three Clerks of the Registry: but we cannot tell which one is the artist himself. They look like portraits, but it is now impossible to tell if this is so. However, there are also drawings of more socially important persons, such as the Rector Magnificus of the University, whose official likenesses have survived: further research may show if Boonen was attempting a portrait.

Boonen’s History was published in 1880 by the distinguished local historian Edward van Even. He had preceded this in 1863 with an illustrated edition of the ommegang section. The engravings by L. Van Piteghem made Boonen’s drawings available to a wider public, and have been used by medieval theatre historians as evidence for pageant-waggon staging. Van Piteghem’s versions (on the left, his Virgin of the Annunciation) now look ‘Victorian’ in comparison with their lively Mannerist originals (on the right, Boonen's).

An academic rumour circulated in the English-speaking world that the original manuscript had vanished in one of the two destructions of the University Library in 1914 and 1940, and that Van Even was its only remaining witness. Meg Twycross’ article on ‘The Flemish Ommegang and its Pageant Cars’ in Medieval English Theatre 2 (1980) assumed this with the rest. Fortunately this was not so: the manuscript belonged to the City Archives, not the University, and now reposes honourably in the Museum Mertens-Van Der Kelen in Savoyestraat.

Professor Twycross and Dr Guido Latré (of the English Department in the Katholieke Universiteit Leuven) are making a bi-lingual (English/Dutch) edition of the text and pictures of the ommegang portion of the Liber Boonen.