Though Michael's successor Andronikos II quickly repudiated the Union of the Churches, many of the Palaiologan emperors worked to ensure its restoration. As the Ottoman Empire grew to encompass more and more Byzantine territory, emperors such as John V and Manuel II labored intensely to retore the union, much to the dismay of their subjects. At the Council of Florence in 1439, Emperor John VIII reaffirmed the Union in the light of imminent Turkish attacks on what little remained of his empire. To the Byzantine citizens themselves, the Union of the Churches, which to John VIII served as an assurance of a great western crusade against the Ottomans, was a death warrant for their empire. John VIII had betrayed their faith and as such their entire imperial ideology and world view. The promised crusade, the fruit of John VIII's labor, ended only in disaster as it was defeated by the Turks at the Battle of Varna in 1444. In 1798, the Greek Orthodox Patriarch of Jerusalem, Anthemus, wrote that the Ottoman Empire had been imposed by God himself as the supreme empire on Earth due to the heretical dealings of the Palaiologan emperors with Christians in the West.