This reputation exceeds the truth in at least two recorded instances. In 1071, after Emperor Romanos IV Diogenes was defeated by Sultan Alp Arslan, a palace coup was staged before he could return to Constantinople. Caesar John Doukas used the Varangian guard to depose the absent emperor, arrest Empress Eudoxia, and proclaim his nephew, stepson of Diogenes Michael VII, as emperor. Thus, instead of defending their absent emperor, the Varangians were used by the usurpers—proving their loyalty to the throne, if not always the current occupier of that throne. In a more sinister episode, the historian Joannes Zonaras reports the guard revolting against Nikephoros III Botaneiates after the blinding of the general Nikephoros Bryennios in 1078, "planning to kill him" but being suppressed by loyal troops. They subsequently asked for and received a pardon.