evolved
... that the role of the Rhodesian head of government gradually evolved, between 1890 and 1970, from that of a company-appointed administrator to the prime ministerial office of a republic?
... that the role of the <a href="./Rhodesia" id="mwDnE" rel="mw:WikiLink" title="Rhodesia">Rhodesian</a> head of government gradually <b id="mwDnI"><a class="mw-redirect" href="./History_and_evolution_of_the_Rhodesian_premiership" id="mwDnM" rel="mw:WikiLink" title="History and evolution of the Rhodesian premiership">evolved</a></b>, between 1890 and 1970, from that of a <a href="./British_South_Africa_Company" id="mwDnQ" rel="mw:WikiLink" title="British South Africa Company">company</a>-appointed administrator to the prime ministerial office of a republic?