The <a href="https://en.wikipedia.org/wiki/Penny_Black" id="mwXQ" rel="mw:WikiLink" title="Penny Black">Penny Black</a>, the first official adhesive <a href="https://en.wikipedia.org/wiki/Postage_stamp" id="mwXg" rel="mw:WikiLink" title="Postage stamp">postage stamp</a>, is issued in the <a href="https://en.wikipedia.org/wiki/United_Kingdom" id="mwXw" rel="mw:WikiLink" title="United Kingdom">United Kingdom</a>.