Ivan the Russian
... that medieval Bulgarian military leader Ivan the Russian defended Plovdiv in a four-month Byzantine siege only for the citizens to let the Byzantines in while he was away?
... that <a href="./Second_Bulgarian_Empire" id="mwBG4" rel="mw:WikiLink" title="Second Bulgarian Empire">medieval Bulgarian</a> military leader <b id="mwBG8"><a href="./Ivan_the_Russian" id="mwBHA" rel="mw:WikiLink" title="Ivan the Russian">Ivan the Russian</a></b> defended <a href="./Plovdiv" id="mwBHE" rel="mw:WikiLink" title="Plovdiv">Plovdiv</a> in a four-month <a href="./Byzantine_Empire" id="mwBHI" rel="mw:WikiLink" title="Byzantine Empire">Byzantine</a> siege only for the citizens to let the Byzantines in while he was away?