simultaneously as residential bishops
... that the cardinals were not allowed to serve simultaneously as residential bishops until the pontificate of Alexander III?
... that the <a class="mw-redirect" href="./Cardinal_(Catholicism)" id="mwCNA" rel="mw:WikiLink" title="Cardinal (Catholicism)">cardinals</a> were not allowed to serve <b id="mwCNE"><a href="./External_cardinal" id="mwCNI" rel="mw:WikiLink" title="External cardinal">simultaneously as residential bishops</a></b> until the pontificate of <a href="./Pope_Alexander_III" id="mwCNM" rel="mw:WikiLink" title="Pope Alexander III">Alexander III</a>?