between Poland and Russia
... that the Polish-Lithuanian union of Lublin in 1569 marked the beginning of centuries of struggle between Poland and Russia over Central and Eastern Europe?
... that the <a class="mw-redirect mw-disambig" href="./Polish-Lithuanian" id="mwCGM" rel="mw:WikiLink" title="Polish-Lithuanian">Polish-Lithuanian</a> <a href="./Union_of_Lublin" id="mwCGQ" rel="mw:WikiLink" title="Union of Lublin">union of Lublin</a> in 1569 marked the beginning of centuries of struggle <b id="mwCGU"><a class="mw-redirect" href="./Polish-Russian_relations" id="mwCGY" rel="mw:WikiLink" title="Polish-Russian relations">between Poland and Russia</a></b> over <a href="./Central_Europe" id="mwCGc" rel="mw:WikiLink" title="Central Europe">Central</a> and <a href="./Eastern_Europe" id="mwCGg" rel="mw:WikiLink" title="Eastern Europe">Eastern Europe</a>?