In April 1204, a Western crusading army on its way to the Holy Land attacked and occupied the Eastern Roman capital of Constantinople in the notorious debacle of the Fourth Crusade. Pope Innocent III had adamantly forbidden the detour but lost control over the army. After the siege
was successful, he seems to have wanted at least to use the conquest to effect a forced reunion of the churches East and West. In this frame of mind Innocent later explained to Theodore Laskaris, Emperor of Nicaea, who had complained that an army commissioned to aid the Holy Land had instead
turned their crusading swords against fellow Christians, that the conquest was the result of inscrutable divine providence of just judgment. Greek insubordination to Rome was an evil, as he explained, that met the evil of the crusaders’ greed and deception (Registrum, ed. Hageneder,
vol. 11, 63). Innocent was not allowed to remain complacent, however; for when the reunion failed to happen and even citizens and soldiers began moving from Jerusalem to the conquered Eastern Roman capital, the pope again reproached the aggressors.