From Barbara Tuchman, The Guns of August:
On August 25 the burning of Louvain began. The medieval city on the road from Liège to Brussels was renowned for its University and incomparable Library, founded in 1426 when Berlin was a clump of wooden huts. Housed in the fourteenth century Clothworkers’ Hall, the Library included among its 230,000 volumes a unique collection of 750 medieval manuscripts and over a thousand incunabula. The façade of the Town Hall, called a “jewel of Gothic art,” was a stone tapestry of carved knights and saints and ladies, lavish even of its kind. In the church of St. Pierre were altar panels by Dierik Bouts and other Flemish masters. The burning and sack of Louvain, accompanied by the invariable shooting of civilians, lasted six days before it was called off as abruptly as it began.