Tranquil Star
... that Tranquil Star is the only mare to have won the double of the Caulfield Stakes, now known as the Yalumba Stakes, and the Cox Plate?
... that <b id="mwBnw"><a href="./Tranquil_Star" id="mwBn0" rel="mw:WikiLink" title="Tranquil Star">Tranquil Star</a></b> is the only <a href="./Mare" id="mwBn4" rel="mw:WikiLink" title="Mare">mare</a> to have won the double of the <a href="./Caulfield_Stakes" id="mwBn8" rel="mw:WikiLink" title="Caulfield Stakes">Caulfield Stakes</a>, now known as the Yalumba Stakes, and the <a class="mw-redirect" href="./Cox_Plate" id="mwBoA" rel="mw:WikiLink" title="Cox Plate">Cox Plate</a>?