Answer
The Doukas family played a pivotal role in the overthrow of Romanos IV Diogenes, the Byzantine emperor, in 1071. The Doukas clan, led by John Doukas, took advantage of Romanos' disastrous defeat at the Battle of Manzikert against the Seljuk Turks to stage a rebellion. John Doukas accused Romanos of neglecting his duties and demanded his abdication.