Any book printed during the early period of book printing (from 450 to 1500) deserves the special interest of bibliographers. Both cultural historians and librarians cannot fail to be excited by the discovery at the end of the 20th century of an ancient book, previously unregistered the general catalogues, in the restored Aglona Basilica library. It is a well-preserved incunabulum in its original binding: Clemens V (papa 305-1314). Constitutiones. - Basel: Michael Wenssler, VI Non. Mai, [2. ai, post. 2 Mail, 1476. - 2°,  f. [GW 7088]. Moreover, glued to the side of the covers are metal engravings made in Germany during the 1470s. Considering there are only 261 incunabula in Latvia, the recently found example from Aglona is of exceptional significance. The newly found incunabulum had been owned by the Riga patrician Reinhold Soltrump (Reynoldus Saltrumpp), son of the Burgermeister and clergyman Johann Soltrump. Information on Soltrump's life is sparse - he describes himself as Magister ac decretorum baccalaureus, clericus Rigensis, a lawyer and Riga clergyman who studied law at the University Leipzig. It is likely that about 1477 Soltrump returned to Riga and joined the city's bibliophile circles. Soltrump used to decorate his books himself, so he was an amateur illuminator. It seems that he was most keen on decorating books with blue and red initials during his study years. Shortly after, ca. 1475-1477, Soltrump decorated many large initial letters with four-leaf ornaments, drew faces in the initials, embellished pages with large monograms instead of initials. This amusing aspect allows us to call Soltrump the master of Riga fish initials, because many of his prolonged initials turn into expressive images of fish. Soltrump was not a skilled draftsman, some initials are rather robust and even superficial; capital letters have wide, gig and heavy legs; his fish and faces are immaturely comical or grotesque. Although the drawing of initials is not accurate and the gouache paint of low quality, he is surely one of the first illuminators in Riga whose handwriting is unmistakable and many works are easily attributed.