In Holland the first books which bear the name of their printer and date and place of imprint are those produced at Utrecht by Nicolaus Ketelaer and Gerardus Leempt, who began work in 1473. It is tolerably certain, however, that some of the so-called "Costeriana" (see Chap. II) preceded this date, and they are at least as likely to have been printed at Haarlem as at Utrecht, there being no decisive evidence in favour of either place. No namable printer appears at Haarlem until the end of 1483, when Jacob Bellaert set up a short-lived press there. For some seven years (1477-84) excellent work was done at Gouda by Gerard Leeu, who then moved to Antwerp. At Delft, where a fine Bible was printed by Jacob Jacobszoen and Mauricius Yemantszoen in 1477, printing was kept up continuously by Jacobszoen, Christian Snellaert, and Hendrik Eckert till the end of the century, though there seems to have been only work enough for one firm at a time. At Zwolle, Pieter van Os, who began work in 1479, was able to maintain himself, with a brief interval about 1482, till past the magic date 1500. Lastly, at Deventer, where Richardus Pafraet started in the same year, an output was speedily attained greater than in any other Dutch town, and for the latter years of the century a rival firm, that of Jacobus de Breda, shared Pafraet's prosperity. The great majority of the Deventer books, however, belong to the minor literature of ecclesiasticism and education, and are far from exciting. The beginnings of printing are much more interesting in the Southern Netherlands, which correspond roughly to what we now call Belgium. Here also the first positive date is 1473, the year in which Johann of Paderborn in Westphalia, best known to English collectors as John of Westphalia, printed three books at Alost. A fourth followed in May, 1474, but by the following December John had removed to Louvain, a University town, where he remained doing excellent and abundant work till nearly the end of the century. At Louvain he had found another printer, Jan Veldener, already in the field, and seems to have hustled him away not very honourably. Veldener, however, was not ruined, but is subsequently found at Utrecht and Kuilenburg, and again for a short time at Louvain.