The Counts of Holland maintained meticulous records of the maintenance of their possessions starting around 1300. New research into these comital accounts provides a unique insight into how the maintenance was organized, which building materials were used, and who carried out the work and at what salary. It appears that the count employed his own team of craftsmen who, in addition to a salary, also received annual payments and clothing allowances. They worked alongside local craftsmen and labourers.

Several renovations on Middelburg Castle and Nieuwburg Castle from the 14th and 15th centuries will be discussed, showcasing the diversity of tasks, people, and resources involved.