slavery in Poland
... that slavery in Poland existed during the Middle Ages, but eventually disappeared with the transformation of slaves into serfs?
... that <b id="mwDCQ"><a href="./Slavery_in_Poland" id="mwDCU" rel="mw:WikiLink" title="Slavery in Poland">slavery in Poland</a></b> existed during the <a href="./Middle_Ages" id="mwDCY" rel="mw:WikiLink" title="Middle Ages">Middle Ages</a>, but eventually disappeared with the transformation of slaves into <a class="mw-redirect" href="./Serfs" id="mwDCc" rel="mw:WikiLink" title="Serfs">serfs</a>?