The Council was mainly devoted to an attempt at unifying the Latin and Greek Churches, which the Western European powers had made a condition for providing military support to Palaiologos as he attempted to fend off the Ottoman Turks. As a member of the Greek delegation, the young Bessarion was not eager to concede the main dogmatic point of disagreement between the two churches, which had led to their separation in the eleventh century: the problem of the place of the Holy Spirit in the Creed. According to the Greeks the Spirit proceeded only from the Father, while in the Roman formulation it also proceeded from the Son (Filioque). And yet, driven by his concern for the unstable political situation in Greece and finally convinced by the texts of the Church Fathers, Bessarion changed his mind and in April 1439 pronounced an oration (the Oratio dogmatica de unione), in which he advocated for agreement between Greek and Latin authors. In July 1439 Bessarion read the act of union between the Roman and the Greek Church in Florence. The same year, while he was in Greece for the last time, Bessarion was made Cardinal.