Siege of Jerusalem
When First Crusade's Siege of Jerusalem ended successfully for the crusaders, the patriarchate of Jerusalem was vacant, and the crusaders elevated a Latin patriarch without reference to either the Roman Catholic or the Eastern Orthodox churches. An Orthodox candidate for the patriarchate was forced to flee to Constantinople. Only when Saladin's Siege of Jerusalem was concluded and the city was returned to Muslim control were the Orthodox Christians allowed to practise in the Church of the Holy Sepulchre.