This book deals with the diminishing role of the militias in West Lauwers Frisia around 1500, when this part of the Low Countries lost its communal government, as part of the so-called Frisian freedom. In 1498, after a period of bloody internal strife, Frisia became a territory of Albert of Saxony. In 1515, Charles V incorporated it into his Burgundian-Habsburg possessions. Until 1524, he had to subdue the unwilling Frisians receiving assistance from his rival Charles II of Guelders. Although Charles V had conquered Frisia mainly with trained mercenaries, sieges, and raids, he still appreciated the deployment of unprofessional militias. They saved his treasury, brought numerical preponderance, and could cope with the marshy Frisian lands, in which cavalry was useless. This explains why the Habsburgs continued the presence of militias, and urged the Frisian authorities to organize inspections and the creation of muster rolls when attack was imminent.

Hans Mol, scholar in medieval studies at the Frisian Academy (Leeuwarden) and professor of medieval Frisian history at Leiden University, provides with this study far more than its title suggests. He integrated his main topic perfectly into both the context of late medieval and early modern military professionalization, and the sixteenth-century state formation in the Low Countries. Furthermore, the analytical part of the book (until page 173) is useful as a general introduction to the history of Frisia in the first half of the sixteenth century. Its structure, however, is rather unusual. After an introductory chapter, the author discusses the period 1525–52, before the period 1480–1524. Mol explains this ordering by stating that we do not have suitable sources about the organization and armament of the militias in the older period. Although it analytically works in the body, the conclusion repeats the same structure—even though this is a place where the chronological order could have been maintained.

In any case, Mol convincingly demonstrates that the Frisian militias always remained inferior to the contemporary paid soldiers. The muster rolls, for instance, mention their simple weaponry—especially the weaponry of those in the countryside. This is not a surprising conclusion, of course. Nevertheless, this study makes clear that the story is more diverse than has been narrated until now. Within such a context, it would have been great to know how many members of the Frisian militias did become professional mercenaries. Unfortunately, Mol could only address this with little evidence, such as the visual material about Emperor Maximilan's army, in which Frisians were called Springer (jumpers) because of their long pikes. These weapons were also used as poles for jumping over ditches, which is still a popular sport in Frisia, called fierljeppen.

Half of the publication is filled with a transcription of the surviving Frisian muster rolls of 1552 and those of the isle of Ameland—a free lordship—from 1558. These were fantastic sources for Mol's research, since they include not only the names of the men of fighting age and their weaponry but also their residential backgrounds. The original documents concerning Frisia are kept in the State Archives of Belgium, in Brussels, and those regarding Ameland are in the National Archives of the Netherlands, in The Hague. The commemoration at the front of the publication of Onno Hellinga (2011), by Mol and Peter van der Meer, the other editor of the rolls, is well deserved, because Hellinga partially prepared the edition.

The publication's index on personal and topographical names does not encompass the edited rolls. This is understandable considering the number of personal names, but it is a pity that topographical names were not included. Including them in the index could have enabled outsiders to connect the places mentioned in the rolls in sixteenth-century spelling with the modern spelling of those names—for instance, sixteenth-century Colderawaelt with present-day Kolderwolde (Dutch) and Kolderwâlde (Frisian). In his analysis Mol uses the modern Dutch topographical names of Frisian places instead of the present official names, which are partially Frisian. This sounds logical given that the book's language is Dutch. It is, however, also a political choice, since the nineteenth-century Kingdom of the Netherlands recorded official Dutch versions of Frisian names in a rather arbitrary way.