The Pax Mongolica of the 13th and 14th centuries that united vast parts of the European-Asian continents enabled western missionaries to travel east. "Dominican friars were preaching the Gospel on the Volga Steppes by 1225 (the year following the establishment of the Kipchak Khanate by Batu), and in 1240 Pope Gregory IX despatched others to Persia and Armenia." The most famous Dominican was Jordanus de Severac who was sent first to Persia then in 1321, together with a companion (Nicolas of Pistoia) to India. Father Jordanus' work and observations are recorded in two letters he wrote to the friars of Armenia, and a book, "Mirabilia", translated as "Wonders of the East".