Abstract
During the 13th century the Papal Curia made first steps to revive the ecclesiastical unity between Western and Eastern Christendom. This was to be achieved by making Orthodox Christians accept the primacy of the papacy.
When Russian Principalities were struck by the Mongol invasion, the papacy attempted to use the new political situation to spread there its influence. Popes consequently established contacts with Daniil Romanovich, the prince of Galicia-Volyhnia and Alexander Yaroslavich, the prince of Novgorod and subsequently grand prince of Vladimir.
The reactions to the papal diplomatic mission naturally varied. This stemmed from different political situations which their respective domains experienced.