Abstract
The dynasty of Opavian Premyslids ruled in the Duchy of Opava and - since 1337 until their dynastic extinction in 1521 - also in the neighbouring Duchy of Ratibor. Members of the dynasty managed to also take over the rule in the Duchy of Minstrberk, but only for a quite short time in the middle of the 15th century.
The main goal of this study is to highlight universally not very well-known document from 1487. In it, one of the last Přemyslids, the duke John (VI.) of Ratibor (+ 1493), was determined as an heir to his relatives, childless couple Kazimir of Zator (+ 1490) and Margaret of Krnov (+ 1508).
This is being termed as "dobrá vůle (good will)", which corresponds with the transfer (cession) in the manuscript from the 16th century, where the text of the document is preserved. However, according to its content, it was undoubtedly joint testament.
If it would have been respected, the possessions of Přemyslids of Ratibor would increase by the half of the Duchy of Zator, where Kazimir ruled. This territory has been unfortunately in the sphere of influence of the Polish king who was sworn an oath of allegiance by the Zator Piasts few years earlier.
Without his consent, John of Ratibor had practically no chance to gain the vacant possessions. And so, the Duchy of Zator, divided in 1477, was unified only later, again in the hands of Kazimir's younger brothers.
After the extinction of the Zator branch of Piast dynasty, Zator gradually became an integral part of the Polish Crown. The last Přemyslids then aimed their attention to the possibility of future inheritance of much larger and wealthier Duchy of Opole.
Unfortunately, their end came in 1521 when the last of them died unmarried, without children. And so, the first Bohemian royal dynasty became definitively extinct.