The first group of <a href="https://en.wikipedia.org/wiki/Dorsland_Trek" id="mwXQ" rel="mw:WikiLink" title="Dorsland Trek">Dorsland trekkers</a> under the leadership of <a href="https://en.wikipedia.org/wiki/Gert_Alberts" id="mwXg" rel="mw:WikiLink" title="Gert Alberts">Gert Alberts</a> leaves <a href="https://en.wikipedia.org/wiki/Pretoria" id="mwXw" rel="mw:WikiLink" title="Pretoria">Pretoria</a>.