By “siddur” we ordinarily mean a Jewish prayer book, but this volume is not a normal prayer book. It is, rather, a rich compendium of liturgical poetry for Shabbat and the holidays, written in early Ashkenaz. Many of these poems are not included in later prayer books, so what is preserved in this volume offers crucial documentation of otherwise lost Jewish creativity. Also notable in this volume are its numerous miniature illustrations. 

 On the page before you (66b, image 144), you can see two armored knights on horseback, ready for battle. The text, a liturgical poem for Simhat Torah, has no obvious connection with the image, which is similar to those found in other Ashkenazic texts of this period. The connection, rather, is to the surrounding culture of central Europe, of which Jews were very much a part.