Probatus
... that in a letter of 22 April 772 to Probatus, who later served as his ambassador, Pope Adrian I claimed to rule a "republic of the Romans"?
... that in a letter of 22<span id="mwChs" typeof="mw:Entity"> </span>April 772 to <b id="mwChw"><a href="./Probatus" id="mwCh0" rel="mw:WikiLink" title="Probatus">Probatus</a></b>, who later served as his ambassador, <a href="./Pope_Adrian_I" id="mwCh4" rel="mw:WikiLink" title="Pope Adrian I">Pope Adrian I</a> claimed to rule a "republic of the Romans"?