What happened when the Fourth Crusade captured Constantinople in 1204?

When the Fourth Crusade captured Constantinople on April 12, 1204, it resulted in a catastrophic and disgraceful sack of the city. For three days, the crusading army pillaged at will, systematically violating holy sanctuaries, destroying or stealing sacred relics, and assaulting the city's inhabitants.123

Following the violence, the crusaders established the Latin Empire, installing Baldwin of Flanders as emperor and a Venetian as patriarch. The Byzantine Empire fragmented into several quarreling states, including Nicaea, Trebizond, and Epirus, and never recovered its former greatness.123

Although Pope Innocent III had initially forbidden the diversion of the Crusade and later rebuked the crusaders for their conduct, he mistakenly hoped the conquest would reunite the Latin and Greek churches. Instead, the events of 1204 irrevocably weakened the Byzantine Empire and solidified the schism between the Catholic West and the Orthodox East, as the Greeks rejected papal authority upon regaining control in 1261.24