The aim of this study is to analyze the system of taxation developed by the papal government at the time of the fourth crusade, which is one of the main aspects of the political and juridical policy enacted by pope Innocentius III. As will be shown, a special tax, designed by Lotario di Segni continued to be part of the canonical and juridical organization long after the extinction of the peculiar circumstances that originated it. This particular tax in fact, transcending its original purpose of securing economic support, ultimately became a symbol of freedom and independence of the church from any secular power.


Keywords: Innocent III; jus exigendi; “bolla graves orientalis”; Codex Iuris Canonici.