Gustavus
... that in 1821, Gustavus became the first of four grey horses to win the Derby Stakes?
... that in 1821, <b id="mwBx8"><a href="./Gustavus_(horse)" id="mwByA" rel="mw:WikiLink" title="Gustavus (horse)">Gustavus</a></b> became the first of four <a class="mw-redirect" href="./Gray_(horse)" id="mwByE" rel="mw:WikiLink" title="Gray (horse)"> grey horses</a> to win the <a href="./Epsom_Derby" id="mwByI" rel="mw:WikiLink" title="Epsom Derby">Derby Stakes</a>?