Book chapters
Constitutions, Elections and Legislatures of Poland, 1493-1993 by Jacek Jędruch (1998)

Figure 19

Fig. 19 - The keep in the castle or Piotrków. Until 1567 most of the Seyms of the hereditary monarchy convened here, while their membership rose from 54 to 92 Deputies. Shown in the present day condition, it now houses a regional museum.